Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a3626b5ab621055…

MALICIOUS

PDF

72.4 KB Created: 2021-05-18 21:18:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 623306ff811cff3e8d5644b0d88055ea SHA-1: b39d5dd6e9f3280a7aaabfb885eba4e2e3c0400f SHA-256: 0a3626b5ab62105537ba4d8083590ecc158ec11697d915c268a17155630bfd1b
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV both strongly indicate this PDF is malicious, specifically identified as a phishing trojan. The document contains a link farm pointing to multiple domains, some of which are associated with compromised CMS uploads, suggesting an attempt to redirect users to malicious content or downloads. The document body itself is heavily obfuscated and contains metadata related to PDF generation tools, but the primary malicious activity is driven by the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://strahovka66.ru/userfiles/file/37127602779.pdf
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/b07b1cda2e6a71c5657f1faedb69174b/remajanojit.pdf
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/a9c6366c661eefdc8f43741867eac9fb/35682010812.pdf
    • http://technoculture.cz/admin/upload/file/rowide.pdf
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/9clpforn41cgv4d7kl6vt6hfjf/18285233249.pdf
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/dda729890d19f71a819d3642e5e0e32a/sisofimomarupiwatusel.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f80aa8ba53---82052513104.pdf
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/fdc4e5ab8052d3f67ce51f43837b2313/74900581696.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607232e4c370c---46008060308.pdf
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fdead8843d---11452236805.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca58bf3ec4---28259233620.pdf
    • http://andrelandberg.com/userfiles/file/pijowalowavuk.pdf
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16079673e4bdaf---72067692965.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/lh94o80cuv1edgva2p32koj2s0/jojopusefafuzeramopisu.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081d3e82f25f---78330451571.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/rg3ovdd381cmccti5gloadg0r0/80677763186.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160961281cf9dc---jotewunesowinus.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=gta+san+andreas+cheater+apkpure
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc68.bin
9eb613bb674e31fe696220fa3a811eb1479ac5814191db563506731d0cb9a910
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC68 5224 bytes
font_01_sfnt_off0000ee2d.bin
ed33c6f636c6207c1a6e7bde249b1af9e6b285606e688780472ece712ff40d1d
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE2D 11124 bytes