in 2013 , we introduced datalert to monitor and alert on sensitive data and file activity . in 2014 , we introduced datanswers , a secure enterprise search solution for enterprise data that delivers highly relevant and secure search results to enterprise employees , greatly improving their productivity . in 2015 , we enhanced our datadvantage , dataprivilege and data classification engine offerings ; with datadvantage support for the following microsoft office 365 data stores : exchange online , sharepoint online , onedrive and active directory hosted in azure ; with dataprivilege for sharepoint ; and with data classification engine for unix , sharepoint online and onedrive . in 2016 , we enhanced our datadvantage offerings with additional office 365 support ; datanswers support for sharepoint online and onedrive ; and introduced a new web ui for datalert for comprehensive security management and threat detection . in that year we also added additional user behavior analytics driven threat models to datalert to significantly enhance our detection of insider threats , including potential disgruntled employees , rogue administrators , hijacked accounts and malware , such as ransomware . we also established a behavioral research laboratory where a dedicated team of security experts and data scientists from varonis continually research the latest threats and emerging security vulnerabilities and introduce new behavior-based threat models to datalert . in 2017 , we introduced the automation engine to allow customers to automatically repair and maintain file systems so that organizations are less vulnerable to attacks and security breaches , more compliant and consistently meeting a least privilege model . we enhanced datalert with datalert analytics rewind to allow customers to analyze past user and data activity to identify security breaches that may have occurred in the past and pre-emptively tune out false positives . we have continued to update our web ui for datalert and added new threat models to detect suspicious mailbox , exchange and exchange online behaviors , password resets , unusual activity from personal devices and more . we introduced a new security dashboard in datalert , along with enhanced behavioral analytics , geolocation and more to make it easier than ever to perform security investigations and forensics . in 2017 , we also released gdpr patterns , part of the data classification engine family , to help enterprises identify data that falls under the gdpr and expanded our offerings that can help enterprises meet compliance and regulation requirements . finally , in early 2018 , we introduced varonis edge to extend our proactive security approach to the perimeter enabling customers to spot signs of attack at the perimeter with telemetry from dns , vpn and web proxies . at the core of our technology is our ability to intelligently extract and analyze metadata from an enterprise 's vast , distributed data stores . the broad applicability of our technology has resulted in our customers deploying our platform for numerous use cases for security , it , operations and business personnel . we currently have six product families , and , as of december 31 , 2017 , approximately 52 % of our customers had purchased products in two or more families , one of which was datadvantage for all of these customers . we believe our existing customer base serves as a strong source of incremental revenues given our broad platform of products , their growing volumes and complexity of enterprise data and associated security concerns . our maintenance renewal rate for each of the years ended december 31 , 2017 , 2016 and 2015 was over 90 % . our key strategies to maintain our renewal rate include focusing on the quality and reliability of our customer service and support to ensure our customers receive value from our products , providing consistent software upgrades and having sufficient dedicated renewal sales personnel . 29 we sell substantially all of our products and services to channel partners , including distributors and resellers , which sell to end-user customers , which we refer to in this report as our customers . we believe that our sales model , which combines the leverage of a channel sales model with our highly trained and professional sales force , has and will continue to play a major role in our ability to grow and to successfully deliver our unique value proposition for enterprise data . while our products serve customers of all sizes , in all industries and all geographies , the marketing focus and majority of our sales focus is on targeting organizations with 1,000 users or more who can make larger purchases with us over time and have a greater potential lifetime value . as of december 31 , 2017 , we had approximately 6,250 customers , spanning leading firms in the financial services , healthcare , public , industrial , insurance , energy and utilities , consumer and retail , education , media and entertainment and technology sectors . we believe our customer count is a key indicator of our market penetration and the value that our products bring to our customer base . we also believe our existing customers represent significant future revenue opportunities for us . we will continue our focus on targeting organizations with 1,000 users or more who can make larger purchases with us over time . the average spending per customer for each of the years ended december 31 , 2017 , 2016 and 2015 was approximately $ 83,000 , $ 65,000 and $ 59,000 , respectively . we believe there is a significant long term growth opportunity in both domestic and foreign markets , which could include any organization that uses file shares , intranets and email for collaboration , regardless of region . story_separator_special_tag cost of revenues and gross margin year ended december 31 , 2017 2016 % change ( in thousands ) cost of revenues $ 20,873 $ 15,843 31.7 % replace_table_token_11_th the increase in cost of revenues was primarily related to an increase of $ 3.7 million in salaries and benefits and stock based compensation expense due to increased headcount for support personnel to support our greater revenues and high renewal rate and a $ 0.9 million increase in facilities and allocated overhead costs . 35 operating costs and expenses replace_table_token_12_th replace_table_token_13_th the increase in research and development expenses was primarily related to an increase of $ 8.7 million in salaries and stock based compensation expense resulting from increased headcount as part of our focus on enhancing and developing our existing and new products . the remainder of the increase was attributable to a $ 1.6 million increase in facilities and allocated overhead costs . the increase in sales and marketing expenses was primarily related to a $ 23.4 million increase in salaries and benefits and stock based compensation expense due to increased headcount to expand our sales force , and commissions on increased customer orders . the remainder of the increase was attributable to a $ 3.3 million increase in facilities and allocated overhead costs and a $ 0.6 million increase in marketing related expenses . the increase in general and administrative expenses was primarily related to an increase of $ 5.0 million in salaries and benefits and stock based compensation expense due to increased headcount to support the overall growth of our business and an increase of $ 1.6 million of other expenses predominately relating to it . financial income ( expenses ) , net replace_table_token_14_th financial income ( expense ) , net for the year ended december 31 , 2017 was primarily comprised of foreign currency gains compared to foreign currency losses for the year ended december 31 , 2016. income taxes year ended december 31 , 2017 2016 % change ( in thousands ) income taxes $ ( 2,459 ) $ ( 1,131 ) ( 117.4 ) % income taxes for the years ended december 31 , 2017 and 2016 were comprised primarily of foreign income taxes and state taxes . 36 comparison of years ended december 31 , 2016 and 2015 revenues replace_table_token_15_th replace_table_token_16_th total revenue growth was achieved due to increased demand for our products and services from existing and new customers , mostly in the domestic market , as well as in international markets . the increase in license revenues was driven by sales to 1,098 new customers in 2016 compared to 1,065 new customers in 2015 , sales to existing customers and sales of new products . as of december 31 , 2016 and 2015 , we had approximately 5,350 and approximately 4,350 customers , respectively . almost all of our license revenues was attributable to sales of perpetual licenses . the increase in maintenance and services revenues was primarily due to an increase in the sale of maintenance agreements resulting from the growth of our installed customer base . in each of 2016 and 2015 , our maintenance renewal rate was over 90 % . of the license and first year maintenance and services revenues recognized in the year ended december 31 , 2016 , 58 % was attributable to revenues from new customers , and 42 % was attributable to revenues from existing customers . of the license and first year maintenance and services revenues recognized in the year ended december 31 , 2015 , 63 % was attributable to revenues from new customers , and 37 % was attributable to revenues from existing customers . as of december 31 , 2016 and 2015 , 48 % and 45 % of our customers , respectively , had purchased two or more product families . cost of revenues and gross margin year ended december 31 , 2016 2015 % change ( in thousands ) cost of revenues $ 15,843 $ 12,019 31.8 % replace_table_token_17_th the increase in cost of revenues was primarily related to an increase of $ 3.7 million in salaries and benefits and stock based compensation expense due to increased headcount for support . 37 operating costs and expenses replace_table_token_18_th replace_table_token_19_th the increase in research and development expenses was primarily related to an increase of $ 4.7 million in salaries and stock based compensation expense resulting from increased headcount as part of our focus on enhancing and developing our existing and new products . the increase in sales and marketing expenses was primarily related to a $ 19.6 million increase in salaries and benefits and stock based compensation expense due to increased headcount to expand our sales force , and commissions on increased customer orders . the remainder of the increase was attributable to a $ 1.3 million increase in marketing related expenses . the increase in general and administrative expenses was primarily related to an increase of $ 3.3 million in salaries and benefits and stock based compensation expense due to increased headcount to support the overall growth of our business and an increase of $ 0.4 million of other expenses predominately relating to it . financial expenses , net replace_table_token_20_th for the years ended december 31 , 2016 and 2015 , financial expenses , net were primarily comprised of foreign exchange losses . income taxes replace_table_token_21_th income taxes for the years ended december 31 , 2016 and 2015 were comprised primarily of foreign income taxes and state taxes . 38 quarterly results of operations the following table sets forth our unaudited quarterly consolidated statement of operations data for each of the eight quarters ended december 31 , 2017. the data presented below has been prepared on the same basis as the audited consolidated financial statements included elsewhere in this annual report and , in the opinion of management , reflects all adjustments , consisting only of normal recurring adjustments , necessary for a fair presentation of this data .

liquidity and capital resources the following table shows our cash flows from operating activities , investing activities and financing activities for the stated periods : replace_table_token_26_th on december 31 , 2017 , our cash and cash equivalents and short-term investments of $ 136.6 million were held for working capital purposes and were invested primarily in short-term investments . we intend to increase our investment in capital expenditures in 2018 to support the growth in our business and operations . we believe that our existing cash and cash equivalents , short-term investments and cash flow from operations will be sufficient to fund our operations and capital expenditures for at least the next 12 months . our future capital requirements will depend on many factors , including our rate of revenue growth , the expansion of our sales and marketing activities , the timing and extent of spending to support product development efforts and expansion into new geographic locations , the timing of introductions of new software products and enhancements to existing software products , the continuing market acceptance of our software offerings and our use of cash to pay for acquisitions , if any . 41 operating activities net cash provided by operating activities is driven by sales of our products less costs and expenses , primarily payroll and related expenses , and adjusted for certain non-cash items , mainly depreciation and stock-based compensation , and changes in operating assets and liabilities . changes in operating assets and liabilities are driven mainly by collection of accounts receivable from the sales of our software products and deferred revenues which represents unearned amounts billed to our channel partners , related to these sales . for 2017 , cash inflows from our operating activities were $ 16.4 million , compared to cash inflows of $ 7.3 million for the prior year . our $ 13.7 million net loss included non-cash charges of $ 23.1 million driven primarily by increased headcount of our sales force and r & d personnel .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```liquidity and capital resources the following table shows our cash flows from operating activities , investing activities and financing activities for the stated periods : replace_table_token_26_th on december 31 , 2017 , our cash and cash equivalents and short-term investments of $ 136.6 million were held for working capital purposes and were invested primarily in short-term investments . we intend to increase our investment in capital expenditures in 2018 to support the growth in our business and operations . we believe that our existing cash and cash equivalents , short-term investments and cash flow from operations will be sufficient to fund our operations and capital expenditures for at least the next 12 months . our future capital requirements will depend on many factors , including our rate of revenue growth , the expansion of our sales and marketing activities , the timing and extent of spending to support product development efforts and expansion into new geographic locations , the timing of introductions of new software products and enhancements to existing software products , the continuing market acceptance of our software offerings and our use of cash to pay for acquisitions , if any . 41 operating activities net cash provided by operating activities is driven by sales of our products less costs and expenses , primarily payroll and related expenses , and adjusted for certain non-cash items , mainly depreciation and stock-based compensation , and changes in operating assets and liabilities . changes in operating assets and liabilities are driven mainly by collection of accounts receivable from the sales of our software products and deferred revenues which represents unearned amounts billed to our channel partners , related to these sales . for 2017 , cash inflows from our operating activities were $ 16.4 million , compared to cash inflows of $ 7.3 million for the prior year . our $ 13.7 million net loss included non-cash charges of $ 23.1 million driven primarily by increased headcount of our sales force and r & d personnel .
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 Suspicious Activity Report : in 2013 , we introduced datalert to monitor and alert on sensitive data and file activity . in 2014 , we introduced datanswers , a secure enterprise search solution for enterprise data that delivers highly relevant and secure search results to enterprise employees , greatly improving their productivity . in 2015 , we enhanced our datadvantage , dataprivilege and data classification engine offerings ; with datadvantage support for the following microsoft office 365 data stores : exchange online , sharepoint online , onedrive and active directory hosted in azure ; with dataprivilege for sharepoint ; and with data classification engine for unix , sharepoint online and onedrive . in 2016 , we enhanced our datadvantage offerings with additional office 365 support ; datanswers support for sharepoint online and onedrive ; and introduced a new web ui for datalert for comprehensive security management and threat detection . in that year we also added additional user behavior analytics driven threat models to datalert to significantly enhance our detection of insider threats , including potential disgruntled employees , rogue administrators , hijacked accounts and malware , such as ransomware . we also established a behavioral research laboratory where a dedicated team of security experts and data scientists from varonis continually research the latest threats and emerging security vulnerabilities and introduce new behavior-based threat models to datalert . in 2017 , we introduced the automation engine to allow customers to automatically repair and maintain file systems so that organizations are less vulnerable to attacks and security breaches , more compliant and consistently meeting a least privilege model . we enhanced datalert with datalert analytics rewind to allow customers to analyze past user and data activity to identify security breaches that may have occurred in the past and pre-emptively tune out false positives . we have continued to update our web ui for datalert and added new threat models to detect suspicious mailbox , exchange and exchange online behaviors , password resets , unusual activity from personal devices and more . we introduced a new security dashboard in datalert , along with enhanced behavioral analytics , geolocation and more to make it easier than ever to perform security investigations and forensics . in 2017 , we also released gdpr patterns , part of the data classification engine family , to help enterprises identify data that falls under the gdpr and expanded our offerings that can help enterprises meet compliance and regulation requirements . finally , in early 2018 , we introduced varonis edge to extend our proactive security approach to the perimeter enabling customers to spot signs of attack at the perimeter with telemetry from dns , vpn and web proxies . at the core of our technology is our ability to intelligently extract and analyze metadata from an enterprise 's vast , distributed data stores . the broad applicability of our technology has resulted in our customers deploying our platform for numerous use cases for security , it , operations and business personnel . we currently have six product families , and , as of december 31 , 2017 , approximately 52 % of our customers had purchased products in two or more families , one of which was datadvantage for all of these customers . we believe our existing customer base serves as a strong source of incremental revenues given our broad platform of products , their growing volumes and complexity of enterprise data and associated security concerns . our maintenance renewal rate for each of the years ended december 31 , 2017 , 2016 and 2015 was over 90 % . our key strategies to maintain our renewal rate include focusing on the quality and reliability of our customer service and support to ensure our customers receive value from our products , providing consistent software upgrades and having sufficient dedicated renewal sales personnel . 29 we sell substantially all of our products and services to channel partners , including distributors and resellers , which sell to end-user customers , which we refer to in this report as our customers . we believe that our sales model , which combines the leverage of a channel sales model with our highly trained and professional sales force , has and will continue to play a major role in our ability to grow and to successfully deliver our unique value proposition for enterprise data . while our products serve customers of all sizes , in all industries and all geographies , the marketing focus and majority of our sales focus is on targeting organizations with 1,000 users or more who can make larger purchases with us over time and have a greater potential lifetime value . as of december 31 , 2017 , we had approximately 6,250 customers , spanning leading firms in the financial services , healthcare , public , industrial , insurance , energy and utilities , consumer and retail , education , media and entertainment and technology sectors . we believe our customer count is a key indicator of our market penetration and the value that our products bring to our customer base . we also believe our existing customers represent significant future revenue opportunities for us . we will continue our focus on targeting organizations with 1,000 users or more who can make larger purchases with us over time . the average spending per customer for each of the years ended december 31 , 2017 , 2016 and 2015 was approximately $ 83,000 , $ 65,000 and $ 59,000 , respectively . we believe there is a significant long term growth opportunity in both domestic and foreign markets , which could include any organization that uses file shares , intranets and email for collaboration , regardless of region . story_separator_special_tag cost of revenues and gross margin year ended december 31 , 2017 2016 % change ( in thousands ) cost of revenues $ 20,873 $ 15,843 31.7 % replace_table_token_11_th the increase in cost of revenues was primarily related to an increase of $ 3.7 million in salaries and benefits and stock based compensation expense due to increased headcount for support personnel to support our greater revenues and high renewal rate and a $ 0.9 million increase in facilities and allocated overhead costs . 35 operating costs and expenses replace_table_token_12_th replace_table_token_13_th the increase in research and development expenses was primarily related to an increase of $ 8.7 million in salaries and stock based compensation expense resulting from increased headcount as part of our focus on enhancing and developing our existing and new products . the remainder of the increase was attributable to a $ 1.6 million increase in facilities and allocated overhead costs . the increase in sales and marketing expenses was primarily related to a $ 23.4 million increase in salaries and benefits and stock based compensation expense due to increased headcount to expand our sales force , and commissions on increased customer orders . the remainder of the increase was attributable to a $ 3.3 million increase in facilities and allocated overhead costs and a $ 0.6 million increase in marketing related expenses . the increase in general and administrative expenses was primarily related to an increase of $ 5.0 million in salaries and benefits and stock based compensation expense due to increased headcount to support the overall growth of our business and an increase of $ 1.6 million of other expenses predominately relating to it . financial income ( expenses ) , net replace_table_token_14_th financial income ( expense ) , net for the year ended december 31 , 2017 was primarily comprised of foreign currency gains compared to foreign currency losses for the year ended december 31 , 2016. income taxes year ended december 31 , 2017 2016 % change ( in thousands ) income taxes $ ( 2,459 ) $ ( 1,131 ) ( 117.4 ) % income taxes for the years ended december 31 , 2017 and 2016 were comprised primarily of foreign income taxes and state taxes . 36 comparison of years ended december 31 , 2016 and 2015 revenues replace_table_token_15_th replace_table_token_16_th total revenue growth was achieved due to increased demand for our products and services from existing and new customers , mostly in the domestic market , as well as in international markets . the increase in license revenues was driven by sales to 1,098 new customers in 2016 compared to 1,065 new customers in 2015 , sales to existing customers and sales of new products . as of december 31 , 2016 and 2015 , we had approximately 5,350 and approximately 4,350 customers , respectively . almost all of our license revenues was attributable to sales of perpetual licenses . the increase in maintenance and services revenues was primarily due to an increase in the sale of maintenance agreements resulting from the growth of our installed customer base . in each of 2016 and 2015 , our maintenance renewal rate was over 90 % . of the license and first year maintenance and services revenues recognized in the year ended december 31 , 2016 , 58 % was attributable to revenues from new customers , and 42 % was attributable to revenues from existing customers . of the license and first year maintenance and services revenues recognized in the year ended december 31 , 2015 , 63 % was attributable to revenues from new customers , and 37 % was attributable to revenues from existing customers . as of december 31 , 2016 and 2015 , 48 % and 45 % of our customers , respectively , had purchased two or more product families . cost of revenues and gross margin year ended december 31 , 2016 2015 % change ( in thousands ) cost of revenues $ 15,843 $ 12,019 31.8 % replace_table_token_17_th the increase in cost of revenues was primarily related to an increase of $ 3.7 million in salaries and benefits and stock based compensation expense due to increased headcount for support . 37 operating costs and expenses replace_table_token_18_th replace_table_token_19_th the increase in research and development expenses was primarily related to an increase of $ 4.7 million in salaries and stock based compensation expense resulting from increased headcount as part of our focus on enhancing and developing our existing and new products . the increase in sales and marketing expenses was primarily related to a $ 19.6 million increase in salaries and benefits and stock based compensation expense due to increased headcount to expand our sales force , and commissions on increased customer orders . the remainder of the increase was attributable to a $ 1.3 million increase in marketing related expenses . the increase in general and administrative expenses was primarily related to an increase of $ 3.3 million in salaries and benefits and stock based compensation expense due to increased headcount to support the overall growth of our business and an increase of $ 0.4 million of other expenses predominately relating to it . financial expenses , net replace_table_token_20_th for the years ended december 31 , 2016 and 2015 , financial expenses , net were primarily comprised of foreign exchange losses . income taxes replace_table_token_21_th income taxes for the years ended december 31 , 2016 and 2015 were comprised primarily of foreign income taxes and state taxes . 38 quarterly results of operations the following table sets forth our unaudited quarterly consolidated statement of operations data for each of the eight quarters ended december 31 , 2017. the data presented below has been prepared on the same basis as the audited consolidated financial statements included elsewhere in this annual report and , in the opinion of management , reflects all adjustments , consisting only of normal recurring adjustments , necessary for a fair presentation of this data .

