Malicious PDF — malware analysis report

Static analysis result for SHA-256 269f73d0bd7582c0…

MALICIOUS

PDF

94.7 KB Created: 2021-05-27 08:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: af34edc300417fd5d04c50703dc5fba9 SHA-1: 590e3f920f70dc0876f727c3272152dfdb5f2860 SHA-256: 269f73d0bd7582c08e422ef65796ad34e2813e4b6f5af5a1f05e83e3a07649a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, identified as a link farm, with the primary URL being vilenefex.ru. This suggests a phishing or malware distribution attempt, masquerading as a chess book. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vilenefex.ru/strik?utm_term=chess+endgame+puzzles+book+pdf
    • https://gipazekafasulal.weebly.com/uploads/1/3/4/6/134600210/rinejufej.pdf
    • https://satupagewamikim.weebly.com/uploads/1/3/4/5/134584558/1972493.pdf
    • https://cdn-cms.f-static.net/uploads/4481156/normal_603c658cb8628.pdf
    • https://cdn-cms.f-static.net/uploads/4369311/normal_601380a474dfe.pdf
    • https://cdn-cms.f-static.net/uploads/4463794/normal_5fd1d607b1d40.pdf
    • https://cdn-cms.f-static.net/uploads/4459341/normal_5fdb292752dc0.pdf
    • https://nowitijot.weebly.com/uploads/1/3/4/7/134716658/webudefomirane.pdf
    • https://likukekubusaz.weebly.com/uploads/1/3/1/4/131408788/525047ac4fd8bb.pdf
    • https://bitabado.weebly.com/uploads/1/3/1/4/131436956/15b2a211cf153.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/d10380e8-8769-4bbe-8b62-e06cc56f7a4e/sefuxusame.pdf
    • https://uploads.strikinglycdn.com/files/8789ea71-bc12-4992-848b-16201c8540f9/xixifa.pdf
    • https://uploads.strikinglycdn.com/files/668b2834-6b8a-4741-b93c-53e55f1da356/how_to_turn_on_the_stove_pilot_light.pdf
    • https://uploads.strikinglycdn.com/files/74d2cce6-a36d-4db6-804f-4c9aa89eafc7/dispute_review_board_vs_arbitration.pdf
    • https://uploads.strikinglycdn.com/files/4f9eeda2-4f18-4082-98d8-7eae6ad24ec0/les_miserables_cast_salary.pdf
    • https://uploads.strikinglycdn.com/files/93156700-fae8-4377-9007-e38db83158a7/lubowi.pdf
    • https://uploads.strikinglycdn.com/files/c9187eb4-4ab2-43e7-9e12-9bd71d3a8d6f/vudonikef.pdf
    • https://uploads.strikinglycdn.com/files/00ef6fcc-4965-4eb0-a249-c95c802d7f30/3153927554.pdf
    • https://uploads.strikinglycdn.com/files/38595061-d1d5-429b-94d6-63ee460ef532/duzusak.pdf
    • https://uploads.strikinglycdn.com/files/3f1b9b4d-4c72-4731-86f0-a5dbde78a2ce/monstrous_synonyms_in_hindi_for_class_3.pdf
    • https://uploads.strikinglycdn.com/files/f2017fce-36b7-4987-a697-d3cbdc1e5d9e/liwilajil.pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012582.bin
1ed0322afdd860e9048c7b8bd03b4ba9185428f25886ca70f84d6f77d5be51f2
pdf-font-stream PDF embedded font (sfnt) at offset 0x12582 5388 bytes
font_01_sfnt_off000137ac.bin
38ed7ae3c749ac51a035dee65fedc6d53660f6756d8bc098649f586e4a761d27
pdf-font-stream PDF embedded font (sfnt) at offset 0x137AC 11704 bytes
font_02_sfnt_off00015f41.bin
05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176
pdf-font-stream PDF embedded font (sfnt) at offset 0x15F41 4324 bytes