Malicious PDF — malware analysis report

Static analysis result for SHA-256 c495e03dddb49a63…

MALICIOUS

PDF

107.1 KB Created: 2021-03-31 13:21:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 308c1e124a0ccf2eba56a83068723431 SHA-1: 24f6aff2cfbb2f42daf307bb9b38d686c8804d04 SHA-256: c495e03dddb49a63df9c56bb6c9e3cc53ae29bfa8bdb9e7a2a78706229a13df4
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://zajinet.ru/strik?utm_term=answer+key+for+ap+english+literature+and+composition+practice+exam+section+1 PDF link annotation
    • http://kukusorukabapoj.iblogger.org/brkert_6013.pdfIn PDF document text
    • http://vuwagumewaga.iblogger.org/kafizesadujijebun.pdfIn PDF document text
    • http://judifino.iblogger.org/jowisowizizeferuzirijojo.pdfIn PDF document text
    • https://warororob.weebly.com/uploads/1/3/5/3/135314520/4634352.pdfIn PDF document text
    • http://wowezixuxaxu.22web.org/agile_model.pdfIn PDF document text
    • https://jewelalebun.weebly.com/uploads/1/3/4/5/134585336/5896169.pdfIn PDF document text
    • https://gezonawaja.weebly.com/uploads/1/3/4/6/134685915/6907184.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://93dbb2ad-f1e8-4c6c-adfd-2ef134399473.filesusr.com/ugd/df4650_8fa3f0b30bb34d4482da514758510158.pdf?index=trueIn PDF document text
    • https://eed7fa7e-4f31-4ba6-8269-e73f07ac74c5.filesusr.com/ugd/93374d_93a0a13ba83c4713be9b83018d4ff749.pdf?index=trueIn PDF document text
    • https://8c805f22-5240-4a8e-9b4d-8499607ff1fc.filesusr.com/ugd/76156b_7827ad7e5b544d21a89240c1e3d6f93b.pdf?index=trueIn PDF document text
    • https://592f3795-292b-4eb7-bb82-ca7d83343d16.filesusr.com/ugd/44d997_7a41ea1969054912b86b8950401cc1a3.pdf?index=trueIn PDF document text
    • https://4ebe1e6a-8a13-4145-b3c2-d2faed65f423.filesusr.com/ugd/a67e73_c0bec3772af84a49a7262434371dabb1.pdf?index=trueIn PDF document text
    • https://e0220c8c-c322-4c33-af83-7c5b0fe00b66.filesusr.com/ugd/a771bd_83f62ab16cd74b6ca25b8bd6986d0340.pdf?index=trueIn PDF document text
    • http://bowibimedex.rf.gd/hiatal_hernia_surgery_guidelines.pdfIn PDF document text
    • http://rereroma.epizy.com/juvitubazuwuwapusu.pdfIn PDF document text
    • https://535a9070-e28a-464b-adc5-c02ad08be00b.filesusr.com/ugd/9df9d6_be2168e9e2b4472b8025219d25b56894.pdf?index=trueIn PDF document text
    • https://a6053a4b-6066-498d-92a8-7748b68531bc.filesusr.com/ugd/5f0d2f_f549314f5a204e6282406d189aaa33d1.pdf?index=trueIn PDF document text
    • https://2a0daf8d-7d8f-48a8-9da6-1f2c606fcb3a.filesusr.com/ugd/adb9e1_9435911e2a1e40b18034d90490d45b00.pdf?index=trueIn PDF document text
    • https://c2c662fa-00ac-4c69-bf5d-04da7d6c99e2.filesusr.com/ugd/9b33c5_4b1a41ea1c424ee987202093b42f8f75.pdf?index=trueIn PDF document text
    • https://507d1b22-ea03-4061-a262-f79425337ca2.filesusr.com/ugd/a374b9_0772ffd8ca6b4f0c808e08796c18bd57.pdf?index=trueIn PDF document text
    • https://1dab3517-3db0-43ff-9fd6-b65b51f65b60.filesusr.com/ugd/565485_f146106a11aa4098b8f76468ae2ef7a4.pdf?index=trueIn 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_off0001620a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1620A 5936 bytes
SHA-256: a07e3b2e056491e51335449be136884668ec1d260bf3c7d6f57249fd29882987
font_01_sfnt_off0001763c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1763C 11028 bytes
SHA-256: 6553b87048fa66479ada4d4f7920c06124369ff82609b74384da0bc1d885181b