Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f3e5bf7d5e3fe66…

MALICIOUS

PDF

72.2 KB Created: 2020-12-09 06:45:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 18f39a7a3ff886b9da0d5ce3fe370d3d SHA-1: d0ac0495ef71322ff13e7a52241afe17c66cd796 SHA-256: 1f3e5bf7d5e3fe668a6d3333896fbe64789acdb3eaf92c6f68bc04467f1740df
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains a heuristic indicating a link farm, with one primary external URI pointing to 'https://traffnew.ru/strik?utm_term=coc+2+cheat+codes'. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'cheat codes', suggesting a lure to a malicious site. No scripts were extracted, but the PDF structure itself likely facilitates the redirection.

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://traffnew.ru/strik?utm_term=coc+2+cheat+codes
    • https://cdn-cms.f-static.net/uploads/4413866/normal_5f9ba8259f43e.pdf
    • https://cdn-cms.f-static.net/uploads/4444351/normal_5fb7f1826f816.pdf
    • https://cdn-cms.f-static.net/uploads/4393908/normal_5f9651e5f2e86.pdf
    • https://static.s123-cdn-static.com/uploads/4425727/normal_5fcdb58a9a735.pdf
    • https://cdn-cms.f-static.net/uploads/4367644/normal_5f935afc2b3b7.pdf
    • https://cdn-cms.f-static.net/uploads/4369189/normal_5f88dc8632bcf.pdf
    • https://waxojokizubow.weebly.com/uploads/1/3/4/4/134482073/tidoka-jegimuzibu-wogulosajuvu.pdf
    • http://urluss.com/10t0ft
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/lejivugeleguwod/29890448937.pdf
    • https://s3.amazonaws.com/ginutu/department_of_natural_resources_alaska.pdf
    • https://s3.amazonaws.com/tenunud/33557231837.pdf
    • https://s3.amazonaws.com/woxojuxafopuv/golliwog_s_cakewalk_debussy_sheet_music.pdf
    • https://s3.amazonaws.com/faxaxos/87478118207.pdf
    • https://s3.amazonaws.com/kavitokolezub/45439309761.pdf
    • https://s3.amazonaws.com/venunamazozuzo/xabonitikibopevo.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_off0000de03.bin
44831a27f799c474eec3f84c66f38a31dc1c107f44d3a2b6b357c637e39bb3f5
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE03 4936 bytes
font_01_sfnt_off0000eec4.bin
9fbfef20d7e3265efc631b35b253f99130d58efc2cc9c75a49d68b16f34a2144
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC4 11076 bytes