Malicious PDF — malware analysis report

Static analysis result for SHA-256 846bd5e0385ec902…

MALICIOUS

PDF

95.0 KB Created: 2021-04-24 13:57:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3c68ed6b410ba35d899a06a440bf26ab SHA-1: def036a9c20b6e75b7fe6d8b1206b03364b1a345 SHA-256: 846bd5e0385ec9023146aeb260c96b3d6365503800c0f1cd1ce497f73e8429b8
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one heuristic specifically identifying a 'PDF link farm' suggesting a large-scale distribution effort. The document body, though heavily obfuscated, contains a question about WW1 alliances, likely a lure to encourage clicks on the embedded malicious URLs. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vilenefex.ru/strik?utm_term=what+were+the+2+alliances+in+ww1
    • http://bu-markett.com/3291758663cyvtj.pdf
    • http://fabulouss.space/dikufuews9f.pdf
    • http://bexemusu.mypressonline.com/61272308453.pdf
    • http://vowujebotoza.mywebcommunity.org/ciencias_sociales_definicion.pdf
    • http://xitaboketeloba.iblogger.org/half_ham_oven_temp.pdf
    • http://clyb-wylcan3.space/37715236090vxywc.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://zobatokuvanoz.epizy.com/rae_sremmurd_black_beatles_free.pdf
    • https://3eeb541e-75be-486c-a732-b1e279b2a932.filesusr.com/ugd/eaab1c_6be1c1758c1b481fbef87b215cb6ea9a.pdf?index=true
    • https://26aaa629-0581-4e25-ae32-a194504e59ab.filesusr.com/ugd/2d4e87_7244a7016bca4c1097dfabc3592864e8.pdf?index=true
    • https://6c8ebe11-725c-420b-823a-68bc39d02ad2.filesusr.com/ugd/3e87bf_64f06727d8da417e8895f869aefe44e9.pdf?index=true
    • https://s3.amazonaws.com/wuwabobujasivor/46302630120.pdf
    • https://s3.amazonaws.com/gapuruxumeg/what_is_string_in_python_with_example.pdf
    • https://s3.amazonaws.com/waxegatulo/letuvejijiwow.pdf
    • https://s3.amazonaws.com/wefadep/top_10_tv_show_sites.pdf
    • https://s3.amazonaws.com/pegozegi/50575700316.pdf
    • https://s3.amazonaws.com/zesixefe/61674800514.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_off00013794.bin
e4ad65faaec216b5b0b892527781f3d56f2be4eb5721422b40a96bed2593ee51
pdf-font-stream PDF embedded font (sfnt) at offset 0x13794 5176 bytes
font_01_sfnt_off00014945.bin
f5bf6974ec3153f5463825884ed3a6094b9b01fff7390f24fcc7c8531938e567
pdf-font-stream PDF embedded font (sfnt) at offset 0x14945 11656 bytes