Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c0b1f9d419b7fb…

MALICIOUS

PDF

75.1 KB Created: 2021-06-01 12:45:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: ad5a3cad60f158d75327bb37158aa4a9 SHA-1: 1d81f26efa2f0a6167378b4874a01e64f060bc6d SHA-256: a5c0b1f9d419b7fb58b82e14158633952f56c2fa7ba27752c4720b769ff06540
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 hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers flagged this PDF as malicious, specifically as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and external link farm behavior suggest it's designed to redirect users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://pelibifir.ru/123?utm_term=arithmetic+progression+word+problems+with+solutions+pdf PDF link annotation
    • https://walotowujiko.weebly.com/uploads/1/3/4/5/134582573/gafetewunulelomupugo.pdfIn PDF document text
    • https://dumamawikop.weebly.com/uploads/1/3/0/7/130740251/tetekepodu-govawax-mefenar-mabujefovuri.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417813/normal_5fdd5bc02abe1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393349/normal_60697efda2661.pdfIn PDF document text
    • https://putesoborufo.weebly.com/uploads/1/3/0/8/130814126/bebezix.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379487/normal_5fdbc126504a7.pdfIn PDF document text
    • https://nuniladolu.weebly.com/uploads/1/3/0/7/130775245/e26272.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403417/normal_6067a282a971e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450509/normal_606a8028125b8.pdfIn PDF document text
    • https://romidanunopupef.weebly.com/uploads/1/3/1/1/131163616/monulif-tupisa-vabaduvu.pdfIn PDF document text
    • https://xuwixozewinufub.weebly.com/uploads/1/3/4/7/134702679/masonuvoxalevub.pdfIn PDF document text
    • https://pimidunobesuxig.weebly.com/uploads/1/3/0/9/130970022/2818314.pdfIn PDF document text
    • https://morinuzarisifuf.weebly.com/uploads/1/3/4/2/134234593/jopinekutexatarezox.pdfIn PDF document text
    • https://panulozeti.weebly.com/uploads/1/3/5/3/135351273/8343674.pdfIn PDF document text
    • https://mefinijusigoti.weebly.com/uploads/1/3/4/4/134499215/lapuzakosevaw-xebajupexemop.pdfIn PDF document text
    • https://bapixive.weebly.com/uploads/1/3/4/3/134393773/78ed0fde1.pdfIn PDF document text
    • https://naguruzitu.weebly.com/uploads/1/3/4/3/134369267/rutajaxonokosukari.pdfIn PDF document text
    • https://wafubimuzev.weebly.com/uploads/1/3/4/8/134869603/2125983.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vawaguzidatu.pbworks.com/w/file/fetch/144423993/riganugate.pdfIn PDF document text
    • http://giresizuloki.pbworks.com/w/file/fetch/144444906/jifeziwijupunozerifuzoju.pdfIn PDF document text
    • http://zopujoxobug.pbworks.com/w/file/fetch/144413553/how_to_prepare_income_and_expenditure_account_and_balance_sheet.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_off0000e57a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE57A 5580 bytes
SHA-256: 551464c607089c2d06966e30c9f464be495c0ad6b150095ca8264506f909490c
font_01_sfnt_off0000f85e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF85E 11324 bytes
SHA-256: 126f136c1ee1dac8eb77b17dc9a46f35ca835003d90b11e81eb77784c2ec6238