Malicious PDF — malware analysis report

Static analysis result for SHA-256 44b9ae934b562d1f…

MALICIOUS

PDF

94.8 KB Created: 2021-01-06 09:28:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: f93579908e5b5e60b27caf7cd0b4cb4f SHA-1: 1cf07971e886c70dd9d9f586b7fdb0d7011f2682 SHA-256: 44b9ae934b562d1f3df4c1fa886f02b03288b6629b4173991ebee18f35fadf1d
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan variant. The heuristic firings reveal it functions as a link farm, containing numerous external URIs pointing to disposable hosting domains. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://traffset.ru/123?utm_term=happy+new+year+2020+blessings PDF link annotation
    • https://rogubadivuna.weebly.com/uploads/1/3/4/3/134337887/redigakavafafupu.pdfIn PDF document text
    • https://cdn.sqhk.co/rijakobebux/cY3jbBB/belching_and_indigestion_ibs.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457848/normal_5fa37e9759830.pdfIn PDF document text
    • https://jobikituloxexe.weebly.com/uploads/1/3/4/4/134456837/vekojug.pdfIn PDF document text
    • https://sapakokejepudig.weebly.com/uploads/1/3/4/4/134457578/22619e4662354bd.pdfIn PDF document text
    • https://keniwuki.weebly.com/uploads/1/3/1/4/131483234/32e063a95e.pdfIn PDF document text
    • https://neverazu.weebly.com/uploads/1/3/4/9/134901342/237967.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371808/normal_5f8e5c6287bf7.pdfIn PDF document text
    • https://cdn.sqhk.co/wiberini/jighJy6/uncharted_2_fortune_hunter_edition_ebay.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4501980/normal_5fc747dbc987e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4386366/normal_5fe3317de7ef2.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://uploads.strikinglycdn.com/files/183d99ba-2eab-4d2a-9872-05afb013c9c1/5306205999.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9de89c2-1d6c-4a86-9ad8-526b1194633b/lebegilewo.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_off0001265c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265C 5152 bytes
SHA-256: 31f22d0b7600d3125272e69d6a54e3856a4aeb07a665603db15d1cfac05701f9
font_01_sfnt_off000137e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137E6 12520 bytes
SHA-256: 25d4c0690c57496654d1a1d688cc974dd44df24256c7a069df3025a1c6fc2ff0
font_02_sfnt_off00016016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16016 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f

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