Malicious PDF — malware analysis report

Static analysis result for SHA-256 538b7d6f7ab02575…

MALICIOUS

PDF

79.1 KB Created: 2021-03-21 04:40:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: a3155d755d44f0a9a31a9ca98ea2ccba SHA-1: dee8a71f9a61090896dd5a10ea1b2710c1de8634 SHA-256: 538b7d6f7ab02575be69239bee5f40f58651b0ee0726bfe2593fee147df6313b
186 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a link farm, containing numerous external links, many hosted on disposable domains. The primary malicious URL identified is https://seumen.ru/123?utm_term=app++free+jio+phone, which is likely used for phishing or to distribute further malware. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://seumenha.ru/123?utm_term=app++free+jio+phone PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4379856/normal_5ffd52de9df3c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388038/normal_6015b7035e6ca.pdfIn PDF document text
    • https://cdn.sqhk.co/bazopaxepifu/ehfDYPr/app_store_portugal.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459936/normal_5fca679ae2240.pdfIn PDF document text
    • https://cdn.sqhk.co/bigulikexupa/f5ymOgd/bepixoruvilepo.pdfIn PDF document text
    • https://cdn.sqhk.co/ributexovek/ic8jaQG/cheats_for_minecraft_dungeons_ps4.pdfIn PDF document text
    • https://cdn.sqhk.co/vipikunowi/Rgfhigg/43481788833.pdfIn PDF document text
    • https://cdn.sqhk.co/jeporikate/jLBS0hd/cartoon_cat_mod_minecraft_pc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411922/normal_604cf13a6ec5c.pdfIn PDF document text
    • https://cdn.sqhk.co/riketumes/iypjiji/jumapidejorinoxajinewuxe.pdfIn PDF document text
    • https://cdn.sqhk.co/jitolado/himArcB/jazoxoruferug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383925/normal_6029df9f7ae5b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://80c93ba6-74df-4afb-9852-3a83eaba20e3.filesusr.com/ugd/4cf28d_3e21c065722c43bdbfe549d60439c5cd.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/98da27e7-d6d4-4c14-8df0-9aabe2595fe1/71638878870.pdfIn PDF document text
    • https://058da8ce-bb30-4b8c-81eb-8903018cac65.filesusr.com/ugd/ab745b_b0089a65d306452996ebd5690320afb8.pdf?index=trueIn PDF document text
    • https://74fc1a11-d445-4ffb-bc6b-7a79e5a65a18.filesusr.com/ugd/097bd5_e656aaafcde1494790b94894b3274c3f.pdf?index=trueIn PDF document text
    • https://fa202315-5cd5-4006-9a99-7c5d4406650e.filesusr.com/ugd/61804c_396cd66008d043179321d7703a0038cc.pdf?index=trueIn PDF document text
    • https://1a6defe7-92a0-4357-8a70-d3bce85d30c9.filesusr.com/ugd/385065_e7963b1d87d74fbda2d777e02173ac1c.pdf?index=trueIn PDF document text
    • https://c8019651-2137-4367-b38e-775fff3f8a75.filesusr.com/ugd/fc5a02_b4db58bf58d447888b1213dd804d0870.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a2adb777-ab16-4654-b9f4-aff895031653/can_you_microwave_a_sweet_potato_before_baking.pdfIn PDF document text
    • https://edb7bb8d-792a-4213-93ec-7f573d37cc74.filesusr.com/ugd/bfd504_f1c8bcd74999484d97960dab7dffbcae.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a767d51-7998-4970-af7a-d8f0647f327f/samsung_s6_will_not_turn_on.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB0C 4632 bytes
SHA-256: 41e3c80eee50bfcc32877c919bef4a5d648e113481a3cc634e2b7b6ec3fdeec1
font_01_sfnt_off00010ad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD2 10596 bytes
SHA-256: 518bc947bcc6b70b5db3093e5bc61dd59cbabfe5f5d139498f0635f2ab242a4a