Malicious PDF — malware analysis report

Static analysis result for SHA-256 29e5f75d6d512854…

MALICIOUS

PDF

84.0 KB Created: 2021-06-03 23:17:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 83f8080535bd77f2db3709e3e00b3f57 SHA-1: 2058eb24874d09376dbdd596fd6d655cf2a6dcab SHA-256: 29e5f75d6d5128545b9f6346c7a32c4cd63fb1842d928bb00db08360d298a61c
186 Risk Score

Malware Insights

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

This PDF file was detected 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 it is part of an SEO spam or phishing campaign. The document body, though heavily obfuscated, appears to be a lure related to a worksheet answer key, directing users to external URLs.

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://queure.ru/pbw?utm_term=lesson+7.6+factoring+polynomials+worksheet+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4407989/normal_60464aab84764.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476593/normal_60b79b08c621c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374203/normal_5fc8f1375aafc.pdfIn PDF document text
    • https://jagalanir.weebly.com/uploads/1/3/1/0/131071056/2912791.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366048/normal_60438a3f5e1a6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4499021/normal_5feb963bb907c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460477/normal_604a1b2c6c085.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460975/normal_601c5c5ecec69.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476010/normal_603ce6d8786b8.pdfIn PDF document text
    • https://kevefavovedejot.weebly.com/uploads/1/3/4/7/134719756/7773095.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447467/normal_60470693033db.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457849/normal_6013b564e91f5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4469106/normal_5fec432199b50.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488339/normal_5fd12b18bceb3.pdfIn PDF document text
    • https://wojagezut.weebly.com/uploads/1/3/0/7/130775605/4595450.pdfIn PDF document text
    • https://xefolulewonud.weebly.com/uploads/1/3/1/4/131406676/403130e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393180/normal_602b8879bf6f8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366959/normal_5fe347c074876.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471959/normal_60374ccab6730.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zabodovojif.pbworks.com/w/file/fetch/144426807/roblox_studio_download_ipad.pdfIn PDF document text
    • http://jajisaparev.pbworks.com/w/file/fetch/144412299/75533067768.pdfIn PDF document text
    • http://zepadatoju.pbworks.com/f/62045824816.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_off0001033c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033C 5896 bytes
SHA-256: 1fbcff711b8549555afbc4875bfc04b08b5bf12e514b36640ab0a5994dc62392
font_01_sfnt_off00011752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11752 12188 bytes
SHA-256: 86848348799d4e52ed1e35f69b8ffc1c445f10253d7ba217b8333653ac454a7c