Malicious PDF — malware analysis report

Static analysis result for SHA-256 939c36c3cd07cbcc…

MALICIOUS

PDF

75.6 KB Created: 2021-06-12 16:20:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 8dda969ea63a7dd3c7385fce7a2af3d3 SHA-1: 8b37320f1c428789dc3bbaefdbd51657b076f917 SHA-256: 939c36c3cd07cbccada109bb1730c323cb7f35b634cd463381ef0c81d567834f
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'crewmak.ru'. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is designed to host many links, suggesting a phishing or spamming intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 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://crewmak.ru/pbw?utm_term=sing+along+carols PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4424013/normal_5fda7661a403c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460680/normal_5fca663f2884e.pdfIn PDF document text
    • https://zazokovorif.weebly.com/uploads/1/3/4/3/134321981/751de2a.pdfIn PDF document text
    • https://xuzumuja.weebly.com/uploads/1/3/1/6/131636792/bewovafiziponamuf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391315/normal_601b38d4f11f2.pdfIn PDF document text
    • https://fedubipogumuwu.weebly.com/uploads/1/3/1/3/131379546/juriwebubakibopa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366022/normal_6023ebb762142.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502817/normal_601d2f7e3af7d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476580/normal_5fe14ab821319.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4472783/normal_6002a633ac904.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407314/normal_601f41e0224aa.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://fulusivijomu.pbworks.com/w/file/fetch/144452937/29028082099.pdfIn PDF document text
    • http://jivevisubido.pbworks.com/f/titatodunifunidizevopatan.pdfIn PDF document text
    • http://gipuwufi.pbworks.com/w/file/fetch/145017585/gta_v_mod_apk_download_android.pdfIn PDF document text
    • http://xozojonurom.pbworks.com/w/file/fetch/144536457/53129092272.pdfIn PDF document text
    • http://finatin.pbworks.com/w/file/fetch/144568566/is-240.b_test_answers.pdfIn PDF document text
    • http://rejututaguz.pbworks.com/w/file/fetch/145170714/27252332114.pdfIn PDF document text
    • http://jedilukiwo.pbworks.com/f/jesefofovolufimunafez.pdfIn PDF document text
    • http://papoxuva.pbworks.com/f/vejitisaketesorilewezuvi.pdfIn PDF document text
    • http://zufumegi.pbworks.com/w/file/fetch/144422691/how_long_do_you_cook_frozen_lasagna_in_a_convection_oven.pdfIn PDF document text
    • http://gufabewa.pbworks.com/w/file/fetch/144559935/kenmore_elite_oasis_washer_error_codes_f51.pdfIn PDF document text
    • http://kiwazotomija.pbworks.com/f/46522299425.pdfIn PDF document text
    • http://ditidema.pbworks.com/f/21173125204.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_off0000ded8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDED8 4660 bytes
SHA-256: 3ef8abd47df8cfc4cb1156e6ac0f8e7788d4f219c1e5f3d4cb44519a9ae42fd7
font_01_sfnt_off0000ee8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8B 10612 bytes
SHA-256: a10fbadaa94f40e7b76dab476eed15233c58b8d2965dfd21ada9aa41e164acf3
font_02_sfnt_off000112e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E3 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176