Malicious PDF — malware analysis report

Static analysis result for SHA-256 cff9e780f62fc353…

MALICIOUS

PDF

103.6 KB Created: 2021-07-01 14:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2196733d05fffa178fbd0044796362c5 SHA-1: ef3f13d14763f7aa795a372bfd71c17214dacffc SHA-256: cff9e780f62fc3533c698a2a1d0a73c87d4f2ddbdc78233410b6476000f7ed0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the link farm and the PDF structure suggest it could be used to deliver a second-stage payload, potentially via JavaScript exploits within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://cnex.cc/images/blog//file/koxosuluzinolaxuzutapipu.pdf
    • https://soudurelausiere.ca/upload/editor/file/37178516072.pdf
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbceb8a52f8---67250549849.pdf
    • http://diysmart.net/userfiles/file/82157173726.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/35108850770.pdf
    • http://apisicul.com/userfiles/files/82446956677.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094878f97cac---99279192104.pdf
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/33458061327.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c9562a13eaa---pemabafu.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/949b21a17ef2fa1d2d083fc62a92dfb2/betovamoteluxokidizagirad.pdf
    • http://hc6999.com/userfiles/files/tipiz.pdf
    • https://pet-fashion.ro/mm/file/94687841466.pdf
    • http://okeefesreef.com/ckfinder/userfiles/files/gukakefar.pdf
    • http://frangarcia.eu/upload/file/42823462446.pdf
    • https://nationalshield-uae.com/userfiles/files/zegateluvan.pdf
    • http://homespakistan.net/magzine/uploadfiles/file/58547304838.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/2c66e1232b6b8a6383267815e31951c0/13224245439.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608b34b415d8d---84421872048.pdf
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/97000966765.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160893edb65dc4---ketegukodazinawaro.pdf
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16082e7e16b165---5593632301.pdf
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/160a4123cd48e5---16973268987.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/1eirf4o12bchsss1sn3dmo0ldn/84215144777.pdf
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/f3d190917a023d1f3d027ce6a645468f/buxovaxaxufepuwuje.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160aba828ccb3f---pisoju.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=stardew+valley+how+to+care+for+chickens
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012fc2.bin
3f4bb65275361be9bf07394afc1b7a3e527429b6f4062efb81ab6b54afebea3b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FC2 17544 bytes
font_01_sfnt_off00015d96.bin
26e9dd706a653b4a4c937e249a966cf974d8d259142ca3d9384616ed92ff68fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x15D96 11008 bytes
font_02_sfnt_off00017728.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17728 16792 bytes