Malicious PDF — malware analysis report

Static analysis result for SHA-256 168d2c3b4728f41c…

MALICIOUS

PDF

94.4 KB Created: 2021-03-30 01:17:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 350e84d463b9626f2a8bdc1f40cca399 SHA-1: 19d7108b08d9546e774e9d9921d4e7613d9ba07f SHA-256: 168d2c3b4728f41ca0b5b70f0e06decbe6930f17476cabe4f2ed71d0ff4f0d2f
186 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. Numerous external URIs are present, pointing to disposable hosting and potentially malicious content. The document body is heavily obfuscated and appears to be generated content, further supporting the link farm or SEO manipulation attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • 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://midufefew.ru/wix?keyword=hinduism+quiz+questions+and+answers+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4446494/normal_5fdb9e19aca85.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385010/normal_6062329617926.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450240/normal_5fecc4a120931.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383916/normal_6013e46b1b540.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490724/normal_602e6f06a4fe3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469633/normal_601f1e52ab4b5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387713/normal_605f3a166ca2a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4367311/normal_6006ca4dd6a79.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://vumebef.epizy.com/minority_report_summary_sparknotes.pdfIn PDF document text
    • https://c2c662fa-00ac-4c69-bf5d-04da7d6c99e2.filesusr.com/ugd/9b33c5_4288f62e8b7b49d38b1b8853103445ee.pdf?index=trueIn PDF document text
    • https://4d75d3c9-3a4d-4df6-84ab-e48b83d723e5.filesusr.com/ugd/cdb50c_7ab9d748f9894c12855311ec344586dd.pdf?index=trueIn PDF document text
    • https://0e818273-c791-4c7a-b20f-750474b78fe4.filesusr.com/ugd/362633_508dc9ea010d456b8b37c8858ca91dfc.pdf?index=trueIn PDF document text
    • https://200ee3fc-349d-4871-b5c3-2c1c69b60476.filesusr.com/ugd/7b00a0_f3c9e33135ec42a2a0d3a04bad950cea.pdf?index=trueIn PDF document text
    • https://7ae774ad-b64d-4473-a0b1-aa0db1e39e83.filesusr.com/ugd/3e7897_24f8e4c571174436867ff35ae08ab2f7.pdf?index=trueIn PDF document text
    • https://409b2d23-5c1d-402e-97df-26c0da9299b0.filesusr.com/ugd/2e3d42_05232fee20c1423bab5a91566c48aba2.pdf?index=trueIn PDF document text
    • https://081e7fb2-604d-424b-9b75-a58d54a71a44.filesusr.com/ugd/abd6ea_4152b5cff42f401a8eef1ac1b34091d5.pdf?index=trueIn PDF document text
    • https://ae8c1479-5121-4009-b0ed-8259dbb1205b.filesusr.com/ugd/0aff45_6059486de72f412b90bdba4eba7d2a8a.pdf?index=trueIn PDF document text
    • https://2bb9e989-9ce9-409f-aa8a-839f2ea8d3bf.filesusr.com/ugd/9f8cc2_036f97511bca4864bc869d4a0076ddbf.pdf?index=trueIn PDF document text
    • http://lapefub.epizy.com/57857427172.pdfIn PDF document text
    • https://4b4ea461-5266-411b-8735-d5290551f550.filesusr.com/ugd/7fedcf_4554354781484af3a23d489d87aaa9aa.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001282a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1282A 5264 bytes
SHA-256: 216442e7a91bffc5bfa7f99e820a5e18706c3272ca1e4f5b1b8621602be7f5ba
font_01_sfnt_off000139fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139FD 10616 bytes
SHA-256: 5a5068ce4bbf1539c33b8d21da8e7fde0f2c0237b1d98d5de6ae9ecfdd3118e2
font_02_sfnt_off00015e3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E3F 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2