Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bf3290f0edc530f…

MALICIOUS

PDF

107.9 KB Created: 2021-09-17 21:38:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 491931bbb73dd5b1e9b7ea9ab35641b4 SHA-1: 9395acfa6b3fe8a4da6f78f8dc60430f73b60d4f SHA-256: 4bf3290f0edc530f71214373cc5a56da5d021ca50d8d8696923a8ebe0d0a5a12
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lead users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://audidalys.lt/ckfinder/userfiles/files/banupojonapete.pdf
    • http://korvet-sp.ru/userfiles/file/ranaxudexapewo.pdf
    • http://tangiahoang.vn/Images_upload/files/64212053372.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/8a24221820c8e396c20a4bb383814f5a/gumijijixinuvogatusopete.pdf
    • http://kqcme.yiaiwang.com.cn/upload/files/25463699961.pdf
    • https://aokman-drive.com/d/files/xumeraminakisagejo.pdf
    • http://sartoriaventurini.com/userfiles/files/9056052125.pdf
    • http://tangneylaw.com/admin/images/file/kupomawiduropuvofilebuw.pdf
    • http://sbkf.org/files/files/wudadijegizukudur.pdf
    • http://salsainkonstanz.de/media/files/41351507979.pdf
    • https://trimix.bg/UserFiles/File/3115038264.pdf
    • https://horgaszvelem.hu/ckfinder/userfiles/files/juvufili.pdf
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/zawofo.pdf
    • http://nutrizionisti.eu/public/thread/risorse/file/fumizasemanuxoj.pdf
    • http://www.medicellbank.com/userfiles/files/bitagixizipokipozo.pdf
    • http://budaikepkeret.hu/uploads/file/56907156684.pdf
    • http://falconfam.com/ckfinder/userfiles/files/kuvazunidunopuvo.pdf
    • http://alpes-maritimes.proximeo.com/ckfinder/userfiles/files/44257816006.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/14c6d9b480378028cee880b49d155276/75464389572.pdf
    • https://mwasafat.com/uploads/files/wifipofew.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/hvoqee7quvo82vkc96uicil44f/4760893586.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6398982cb---nogemejajorenatiduku.pdf
    • http://eska-lift.ru/userfiles/file/37699175269.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=do+you+need+to+play+dark+souls+1+and+2+before+3
    • 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_off00013ca0.bin
f5c7dbe59c1212dde75fe1d1cab7c4b391ccac2575737691c437a2d2d77c116d
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CA0 11188 bytes
font_01_sfnt_off000156ea.bin
a735d65a75ad40b6c522c322dfbc16e2b0f6783c336035a1b3d0399c1b838133
pdf-font-stream PDF embedded font (sfnt) at offset 0x156EA 19060 bytes
font_02_sfnt_off00018999.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18999 16792 bytes