Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b1b083e5bbf99d6…

MALICIOUS

PDF

81.4 KB Created: 2021-03-18 05:03:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: faded203410c632ad0de3bdc908b7a6e SHA-1: df8ac39b8aa6d8bcdb47eddfe6faed56a3be15e4 SHA-256: 5b1b083e5bbf99d6e05864b39764ec23f3b95d39ac85ef562ce9ca3d6d144c2f
186 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The embedded content, though heavily obfuscated, appears to be related to assembly language tutorials, likely serving as a lure to drive traffic to malicious or spammy websites.

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://pelibifir.ru/award?keyword=assembly+language+8086+tutorial+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4380876/normal_5fe76c9698b5b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467032/normal_6052ae44caad2.pdfIn PDF document text
    • https://cdn.sqhk.co/vomuvojovi/tjgjjX7/flowchart_drawing_tool_free.pdfIn PDF document text
    • https://cdn.sqhk.co/nigalasiline/thcjf2s/56576762349.pdfIn PDF document text
    • https://cdn.sqhk.co/totarujined/eliczqm/bae_systems_inc._platforms_services.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378167/normal_600dd6ce2cad3.pdfIn PDF document text
    • https://xamatokixixite.weebly.com/uploads/1/3/5/3/135336409/f94c953a4.pdfIn PDF document text
    • https://cdn.sqhk.co/tinodifozeza/hV3alyt/rawowilo.pdfIn PDF document text
    • https://cdn.sqhk.co/ruvuwoki/6MIhgiE/office_boy_girl_image.pdfIn PDF document text
    • https://lepudumewo.weebly.com/uploads/1/3/5/9/135962044/7cd2ea41366.pdfIn PDF document text
    • https://cdn.sqhk.co/kejofuvata/gcia9jc/dream_league_soccer_19_kits_barcelona_2020_jdt.pdfIn PDF document text
    • https://cdn.sqhk.co/tororukiwuri/PXhihjg/gba._emu_apk_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/joraxeneli/Kzibfjf/gaweduxetapevutozisuxo.pdfIn PDF document text
    • https://tumirovuwepilu.weebly.com/uploads/1/3/4/6/134603677/nofovedezolelin.pdfIn PDF document text
    • https://cdn.sqhk.co/fakupavod/d9Yjbot/fetilosuxomimamabametatix.pdfIn PDF document text
    • https://cdn.sqhk.co/lexijunibul/ihaq7hb/wuwodiroxuwodigazegom.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
    • https://144ece88-722e-4d59-a9d1-ae16887514c2.filesusr.com/ugd/48b17f_b46c6330ecd34edea41cf3b09a13bc4c.pdf?index=trueIn PDF document text
    • https://626fb5af-1d67-41cb-86ce-204163677ff0.filesusr.com/ugd/9d869b_d6011214c777449c8cec490b97e2faf9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kelukakeb/green_mile_soundtrack.pdfIn PDF document text
    • https://s3.amazonaws.com/xufujofaleki/intelligent_transport_system_seminar_report.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF145 5964 bytes
SHA-256: 406ef6b1448f374989231ddebf51a537b07cbe114f7afe4cf45cd3eb2f2a0d4e
font_01_sfnt_off0001056b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056B 10712 bytes
SHA-256: e754a222a61c8b612ce71ddcbc5d417fafc1f68655151851ce9a31965002518a
font_02_sfnt_off00012a3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A3C 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378