Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a728e2445d555bd…

MALICIOUS

PDF

67.6 KB Created: 2020-12-21 23:09:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 910f5c573f34ca0fe481d31be22e08a8 SHA-1: 745784f166a8beee3e15386ab09229194bb9299d SHA-256: 2a728e2445d555bd8b5ea89abee13db31554534c12ac864d6dbde46fc023b0b4
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with a high-confidence heuristic indicating it functions as a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URIs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://trafffi.ru/123?utm_term=jquery+on+submit+return+false
    • https://static.s123-cdn-static.com/uploads/4446507/normal_5fcf1453bf936.pdf
    • https://kuginipa.weebly.com/uploads/1/3/4/8/134853520/zixozamazofojaliv.pdf
    • https://cdn-cms.f-static.net/uploads/4417140/normal_5f9c1113714c3.pdf
    • https://cdn-cms.f-static.net/uploads/4382420/normal_5f96616e5d9b8.pdf
    • https://bulakivu.weebly.com/uploads/1/3/4/8/134877285/5d137.pdf
    • https://vumukawa.weebly.com/uploads/1/3/4/6/134662430/kabuxazanu-tejevatabu.pdf
    • https://cdn-cms.f-static.net/uploads/4387573/normal_5f96fd08be570.pdf
    • https://rabifupokuwu.weebly.com/uploads/1/3/1/1/131164250/vebokupameseroru.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static1.squarespace.com/static/5fc508b027a199023acff9ea/t/5fd661265b1f6f7539d6f215/1607885095253/beled_ka_full_form.pdf
    • https://uploads.strikinglycdn.com/files/e4c1e8e4-e753-4df0-a371-7a10de6ebb05/sudonodevotixadijamexabap.pdf
    • https://s3.amazonaws.com/viwoxuz/catanzaro_informa_cronaca_di_oggi.pdf
    • https://uploads.strikinglycdn.com/files/dd77d054-f694-4f1d-9efe-94b91e28397c/wugukesadapuso.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bff8.bin
fc410e2d8cc3205eb4ae8e749f07ad6222b713712d66318ec37f009ced1951fb
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFF8 5268 bytes
font_01_sfnt_off0000d1d9.bin
cc95b96bda6235e0a48a25a0d9c978deb88f2ace767a0ff4f64efc06a0c8cae0
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D9 15408 bytes