Malicious PDF — malware analysis report

Static analysis result for SHA-256 981679b0a1cfac25…

MALICIOUS

PDF

99.9 KB Created: 2021-06-12 22:18:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: bbfd689676d05efae8203d165a370e20 SHA-1: c49b5e8d27319fc0d452ae658c1d7cc0026524e8 SHA-256: 981679b0a1cfac252c97657025b135b5a6edf3e66ed0c97cc47012270d26a379
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO manipulation scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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.
  • 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://inwebjor.ru/pbw?utm_term=the+binding+of+isaac+afterbirth+item+list PDF link annotation
    • https://tiwibuvemugijaj.weebly.com/uploads/1/3/0/7/130776889/16fc63.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383928/normal_5fdbdbad1f1d5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365525/normal_6035d63e6cf94.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412775/normal_5fe8bf4b7d6a2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470979/normal_60157f8e93328.pdfIn PDF document text
    • https://witowufagefalob.weebly.com/uploads/1/3/0/7/130738848/6e4ed53b4053ce5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368950/normal_6036060c93d93.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393908/normal_60369814b7dc0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4407552/normal_6008fb5297f60.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412599/normal_5fe027671fc5b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453743/normal_5fd8a0a4735f0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449184/normal_600d05690895c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/c878ce1b-9955-42a4-90b4-e5505dda36fc/what_is_the_chemical_makeup_of_vegetable_oil.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/384e63bb-0e27-436a-9c7f-87736697f66e/18227249810.pdfIn PDF document text
    • http://xefepexa.pbworks.com/f/roman_numerals_in_1_to_100.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc3ee8ef-d19f-4778-845c-fc3351c5a5c0/sirenub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/61a77c4e-36b8-43c6-b8e7-202733cc6659/le_petit_nicolas_le_bouillon_summary.pdfIn PDF document text
    • http://gorixose.pbworks.com/w/file/fetch/144857949/undertale_full_download_pc.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f46b7787-1142-477b-8be3-9f0a5de8c99c/64952499779.pdfIn PDF document text
    • http://wimarolos.pbworks.com/f/what_is_the_answer_to_question_18_on_the_impossible_quiz_2.pdfIn 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_off00014671.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14671 5524 bytes
SHA-256: f203b1985f55e36373f5a1b57814c8531183f86346a9893322bff0c75b2f7127
font_01_sfnt_off00015911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15911 12032 bytes
SHA-256: bdc52beadd414ab104b62f1ccdcc907a2e1d775f519701e472d2393a61403286