Malicious PDF — malware analysis report

Static analysis result for SHA-256 3691ade5137bffdb…

MALICIOUS

PDF

117.5 KB Created: 2021-06-28 10:24:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1a5547b0828dd5971052e389b9e4b0ea SHA-1: 1f3d34c1cf0224134191d501bd1acf4bd13ebea1 SHA-256: 3691ade5137bffdb297d2ace74c6e6e10e484f18a6fb0aa0704316dabf9b113f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm directing users to multiple external websites, with several hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lead users to phishing or malware distribution sites. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bugaboo-buffalo.eu/UserFiles/File/luxiwabafujesefejovapax.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/c07ce0494d0d79189b3deb7c9631bd55/84640261181.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083b840c7edf---88787839443.pdf
    • http://naucseto.cz/storage/laresaneranig.pdf
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/c62f89a6c04bca403b092bc0ff1bb1ea/69071443911.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a599ec142a5---wominafi.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b40efa0832f---favudar.pdf
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/1s83823eovu10im0g3rig198j0/46069172944.pdf
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/d44e847e9493ed7169de452d5fc76396/nexunarinazimupubinewatun.pdf
    • http://animationcoach.com/userfiles/file/wutozejixonawi.pdf
    • http://afghansolar.com/userfiles/file/78640122222.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c818faf412---7223476448.pdf
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/7a07c5069d242923405f6192fbcd46c4/govim.pdf
    • https://atlastoursntravels.com/userfiles/file/taneribamomisabavopalu.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdf34536013---14979643384.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ed3ccd8a2---tedufixodeluf.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16082323c209cf---xavapi.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/cq04svmec5sh6vg1jhoa96afvt/23955500277.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/8d31bfa151154d604ed8863ed5211a27/82919742642.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/e37d43c58856bb6fa905034365829f44/20914056656.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb88c93e8e---dizifetiwupokigimule.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9c75efdb2---zorekivibidekutir.pdf
    • http://bestbuyfromindia.com/userfiles/file/savuloxevajubobidemutum.pdf
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/586eabdbe9540b999b0730002db6c4f4/3321799377.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/3b8d1384f9c7a62f6551b93b62237525/53582701094.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=a+handful+of+dust+quotes
    • 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_off00016c51.bin
66042b88ce4420c46a741fb99ba21a758911e260bdc0c99224cbea0f66cadb75
pdf-font-stream PDF embedded font (sfnt) at offset 0x16C51 17108 bytes
font_01_sfnt_off00019900.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x19900 16792 bytes
font_02_sfnt_off0001b117.bin
ec3624c98064685487e692b1bf098325b84246299d50c45457dec42747783847
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B117 10484 bytes