Malicious PDF — malware analysis report

Static analysis result for SHA-256 21695d51e032da2b…

MALICIOUS

PDF

71.4 KB Created: 2020-12-15 19:47:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a505e319853e088d00d9bc4dd6153a80 SHA-1: ee11a67d7567720967e8bfdf034360e0c61a833c SHA-256: 21695d51e032da2ba040f0ef8777bee32ce0a02702e0a70f44a3521acf528402
96 Risk Score

Malware Insights

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

The PDF file contains numerous external links, a technique often used for SEO link farms or to redirect users to malicious sites. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs further supports this. While no scripts were explicitly extracted, the PDF structure and link farm heuristic suggest an attempt to drive traffic to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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.
  • 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://trafffe.ru/123?utm_term=college+lacrosse+workout+plan
    • https://vexefanakaxaki.weebly.com/uploads/1/3/4/8/134871487/tonokosako.pdf
    • https://dasateju.weebly.com/uploads/1/3/4/5/134582383/2645857.pdf
    • https://zitidatuviwe.weebly.com/uploads/1/3/4/4/134493200/9fdfa69.pdf
    • https://cdn-cms.f-static.net/uploads/4374853/normal_5fb2cab1b48ad.pdf
    • https://cdn-cms.f-static.net/uploads/4384655/normal_5f8ec352a3720.pdf
    • https://rarerosedipise.weebly.com/uploads/1/3/4/8/134876587/b495387de126.pdf
    • https://pasuliwipo.weebly.com/uploads/1/3/1/4/131452824/39aeccf.pdf
    • https://jedunifoxawixe.weebly.com/uploads/1/3/4/4/134458330/wijuzigebu_detiginalagoro.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static1.squarespace.com/static/5fc1771924b06a7eb3033110/t/5fc945ebbb4c035e835f738e/1607026157438/ninja_run_adventure_mod_apk_free_download.pdf
    • https://static1.squarespace.com/static/5fc537998787e879898820f8/t/5fc85a5fd17d55300fab888e/1606965855950/wallpapers_for_girls.pdf
    • https://static1.squarespace.com/static/5fce353649d01c20c204e848/t/5fd73a59102ca46975fe7ba9/1607940699147/xilizasugorogaxoretam.pdf
    • https://static1.squarespace.com/static/5fc5229c2bbd74065821fe32/t/5fd68ef496ed101a3e47b61a/1607896822823/79871483193.pdf
    • https://s3.amazonaws.com/wisatutadi/college_admission_appeal_letter_template.pdf
    • https://s3.amazonaws.com/domegagowevag/acetaldehyde_formation_in_wine.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_off0000da81.bin
67f48b9ed94fa21db000cd38df83880ad7b594507763587ff5c72cad5bf55ffe
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA81 5164 bytes
font_01_sfnt_off0000ec38.bin
275dfd2668679134b081a38d9c04f9b09f7b4ccb81e19d77992434b5d5a7af4c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC38 10788 bytes