Malicious PDF — malware analysis report

Static analysis result for SHA-256 89aecf7af243b1c9…

MALICIOUS

PDF

82.5 KB Created: 2021-09-07 17:07:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 739cf698964359d8b877d08f338edd9a SHA-1: f1249d0ecc367c6cec52dfbfc6f00c8e0b5e9ce3 SHA-256: 89aecf7af243b1c9366aa94131110506bafc38b668999f125ac800b5d410583e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs, many hosted on compromised CMS platforms or disposable domains. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF versions of web pages, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://iohrp.org/f_files/files/remaliwevezesovudugojo.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3f315c98f8.pdf
    • http://bio86.fr/fichiers/51397887304.pdf
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/xokitegexujagakibemexirig.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/1dbaaad7d64914824c71e2bbbf24e6fa/larorepitominevugolekekew.pdf
    • http://sutinlawkrabi.com/ckfinder/userfiles/files/42302362484.pdf
    • http://greatnice.club/updatefiles/file/dofawexodiz.pdf
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/af9162c5a6c15dfec475d5112037ab62/30419026480.pdf
    • http://strap.sk/uploads/files/tuxotogoxapefadi.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9ce5e0ba0f---79143776862.pdf
    • https://pollackmihalyiskola.hu/ckfinder/userfiles/files/53710141527.pdf
    • http://samtle.net/ckupload/files/numunasavivob.pdf
    • http://hbleg.com/admin/userfiles/files/79789085865.pdf
    • https://www.lipca.com/ckfinder/userfiles/files/lipilixoworowerepuredi.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607987e28ea93---46446164352.pdf
    • http://dzbnf.com/upload/file///boguvotojidiferubewu.pdf
    • http://rbtyutj01.com/userfiles/files/47724021534.pdf
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/57248cd48d6b8f0e68f5e8932cea1e7b/rujunuxotudod.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/161234d40cc335---19725667085.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/6b18284f8e358e1ca2af8301583a11ed/10056383087.pdf
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/ef2f28315c063eaaaf043f200c5d5009/koposuxanefumenefize.pdf
    • https://shih-tzu.ro/files/file/12733335654.pdf
    • http://verduciautodemolizioni.it/userfiles/file/60280213140.pdf
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16084bb9777210---dufajawu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=edit+pdf+online+free+unlimited
    • 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_off0000dd0d.bin
74280295bfec91ad533ce226dd79604ec9d6749505906b4a22dc6dea1bb1caa9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0D 10412 bytes
font_01_sfnt_off0000f48c.bin
26c4abe29bca22fb7e5bda16b6e6dae8ae71c7f567db8b1f1ddf150d2a53ae31
pdf-font-stream PDF embedded font (sfnt) at offset 0xF48C 18456 bytes
font_02_sfnt_off0001241e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1241E 16792 bytes