Malicious PDF — malware analysis report

Static analysis result for SHA-256 92f254d7936b3436…

MALICIOUS

PDF

85.8 KB Created: 2021-04-03 10:21:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 33ceb2cf1e3a6b2f1aa24c196b45f6c8 SHA-1: 0000ff7646f9c6d2e7a8393393577eb87b7baa8c SHA-256: 92f254d7936b3436e4469e8a2a169770dcede5c55216546ccec166545b26fc53
186 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a link farm, containing numerous external links to various domains, many of which are hosted on disposable or dynamic DNS services. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or SEO spam. No scripts were extracted, but the sheer volume of outbound links suggests an attempt to redirect users to malicious sites or manipulate search engine rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://golowaki.ru/award?keyword=antigeno+prostatico+libre+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4445532/normal_5fd08edc52770.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419413/normal_5fd8b7ddc889a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489850/normal_60579a7b0e568.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403560/normal_606346897fc0b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493545/normal_606363476f541.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460709/normal_60063e8455624.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416496/normal_5ffc7a54a94c1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393514/normal_5ffd6b94ecc9d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/kovezodepugov/nuwoxanuj.pdfIn PDF document text
    • https://27420876-d215-4860-9a72-f48db0d0c320.filesusr.com/ugd/4062c2_9872bd0ada0f4a3c85474cff7c204496.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tobaziw/37581454812.pdfIn PDF document text
    • https://6c473ef0-402e-45f0-9f95-6bc7e89a6a1a.filesusr.com/ugd/5518c3_bb13a29824cd4cc9bbc000148adba0a1.pdf?index=trueIn PDF document text
    • https://1c437d0a-cccb-4a8a-93f1-39e0b5126915.filesusr.com/ugd/b91566_57e20e9677ab420490af4cdd30c60e0b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pilazi/nubowababofudugexeka.pdfIn PDF document text
    • https://00eaa6b3-f026-4720-b00f-fafb40066352.filesusr.com/ugd/d498be_0fa6a7effd6144b19a2fbf7231cce045.pdf?index=trueIn PDF document text
    • https://c8070bf9-ed42-4c5d-8eb8-ca35ee70f136.filesusr.com/ugd/d38238_753e545be83144a9ac93fd0491246480.pdf?index=trueIn PDF document text
    • https://60659a61-a27b-47ea-8eac-a81775c62269.filesusr.com/ugd/7a7fb1_1faeff7722774ed699de4d0634458af3.pdf?index=trueIn PDF document text
    • https://67a4337f-2b79-4d04-9c1d-2578c80f4945.filesusr.com/ugd/964009_4a8b6f684dad499e889f307ac0833ec0.pdf?index=trueIn PDF document text
    • https://ff9dba89-6132-4485-99c2-ace8a2453124.filesusr.com/ugd/c3f59f_cb8c84328499444c8dc8ee8a648c704b.pdf?index=trueIn PDF document text
    • https://7c3dd69e-6649-485e-b385-36acc2971cd6.filesusr.com/ugd/cf9ff1_9680bb1c67b74f4e89731afa66e08858.pdf?index=trueIn PDF document text
    • https://592f3795-292b-4eb7-bb82-ca7d83343d16.filesusr.com/ugd/44d997_259e01e9865044008c7803d0f165d840.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010d09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D09 5452 bytes
SHA-256: c8d9a8170bdcf172ce77531b69a1b554adfa9467fec7af863174cf4ed7c5cf71
font_01_sfnt_off00011fa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA2 13380 bytes
SHA-256: 1f5c5e3cce01072a1e5d60101a5f5617518f0a00bb9dfdb9c9643679632a5fd2