Malicious PDF — malware analysis report

Static analysis result for SHA-256 a79eaa2cb5f3d8c6…

MALICIOUS

PDF

67.1 KB Created: 2020-11-14 19:49:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 97923067e63add624c86445edcf9ea6c SHA-1: 9144e0e2267b7a14838f47ceaf6c95cbb6caa604 SHA-256: a79eaa2cb5f3d8c645e503a4996ab5f25cddba46a68df9d699642832e9dac1a5
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or link farm attack. It contains numerous external links, with one prominent URL pointing to 'trafftec.ru'. The document body, though heavily obfuscated, suggests a lure related to "Crabbe book answers" to entice users to click on these links. No scripts were extracted, but the presence of many external links indicates a likely attempt to redirect users to malicious or advertising-heavy websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://trafftec.ru/aws?utm_term=crabbe+book+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4383334/normal_5f8be05af273f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365619/normal_5f914c2a80590.pdfIn PDF document text
    • https://lolijigi.weebly.com/uploads/1/3/4/7/134700793/f3250.pdfIn PDF document text
    • https://wofinomedek.weebly.com/uploads/1/3/4/1/134108675/8313406.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420747/normal_5f9c84a9af7a0.pdfIn PDF document text
    • https://siregudak.weebly.com/uploads/1/3/0/7/130738759/mibajonoloxikir-visev.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425506/normal_5f9b3a894ac85.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374686/normal_5f91abea0f4e8.pdfIn PDF document text
    • https://ralezajaxuluw.weebly.com/uploads/1/3/4/6/134623653/2358917.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000cc8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8B 4848 bytes
SHA-256: 25da26a888057cdb5e10b5c3eae512be45fe3c248d07d5755d60e48852d70804
font_01_sfnt_off0000dd25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD25 10300 bytes
SHA-256: 2e568f689858b2a6d597541c5f9905bfa853688626c26fe21988924264a103f3