Malicious PDF — malware analysis report

Static analysis result for SHA-256 b98bfbcf8e8c7cc0…

MALICIOUS

PDF

87.8 KB Created: 2021-07-02 16:57:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82d9576f67357f2ff6de6877634040c7 SHA-1: 86a8c04fead54c96f0459905527724aadf64868e SHA-256: b98bfbcf8e8c7cc01d66da10e6cbdc4e637e9a71b63651f624ac108435960f5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting domains. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection or exploit vulnerabilities, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://omni-links.com/images/blog//file/9152098771.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/lln0lqjv4c8d63c98cmfiu6e86/44425482596.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075ebb3d84b4---72106850827.pdf
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/aamamflff4dbmfn5of3jv2t2ra/69872670854.pdf
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/aabb39fa0df2a8551e99160776d66872/43857851675.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/8e863e0ad90412582426e130ccf94359/47118530342.pdf
    • http://microcement.ua/userfiles/file/xamasopejinitipevena.pdf
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/lbm9n1o7scg4jd75e5m224a7h1/nirutazufilitafol.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/e7e48ab2925d17664fae960ea57c9d72/86002560910.pdf
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/97ec24c3613b55f0ba9ba89bd4bdfd9c/70543562019.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078001cbf5f9---gitadobepexibufidewatir.pdf
    • https://latework.cz/soubory/nifazitogemajejixuza.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b8fafb873b9---likapoxolevizakun.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a803e0e1621---zunafib.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16095f98b46feb---7617029409.pdf
    • http://graviroz.hu/ckfinder/userfiles/files/36431637673.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/72c4482f8d2fdabb6f321024b1284794/39115667707.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160859f8d94e0b---80481005627.pdf
    • http://elsekmont.eu/userfiles/file/mibunevaw.pdf
    • http://domholidays.com/userfiles/file/58099262481.pdf
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/ln9hsrvcpvbmh9fusrolas93c2/40756075376.pdf
    • http://anpo.vn/upload/files/58824242964.pdf
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/rl7vb8nu5u1bcdtiovbe8sdeak/xizir.pdf
    • http://fletcherfamilyreunion.org/clients/52745/File/fuzojodakewamawa.pdf
    • http://musorcentrum.hu/files/article/file/5988256943.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=parts+of+speech+and+their+functions
    • 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_off0000f401.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF401 16792 bytes
font_01_sfnt_off00010c13.bin
a784000f6403ecbf376a34cb08c5cc81f7f94ef0f84d8a506da46fbdd4d1d2ec
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C13 17232 bytes
font_02_sfnt_off000138dd.bin
55e6652fe2b603180efa0e90a73c66c49d0c27677234114a4509275f6a10fd3c
pdf-font-stream PDF embedded font (sfnt) at offset 0x138DD 10772 bytes