Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fe081af0bd5f501…

MALICIOUS

PDF

81.0 KB Created: 2021-04-04 19:55:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: cf71b86f9dd5ea346a7b94c2832050e3 SHA-1: 0b62ca347de21f2d8b08feeca59a996c4e1d8486 SHA-256: 4fe081af0bd5f501ab043ab49b558dbad724735792e753885c1a6b13c35a3a6e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to disposable hosting, indicating a link farm designed to distribute malicious content. The primary malicious URL identified is vilenefex.ru, which is likely used to host phishing or malware delivery pages. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://vilenefex.ru/strik?utm_term=wind+in+the+willows+picture+book+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4424029/normal_605a5940eadac.pdfIn PDF document text
    • https://relitemora.weebly.com/uploads/1/3/4/3/134352419/pamejev.pdfIn PDF document text
    • https://burekanokem.weebly.com/uploads/1/3/1/0/131069897/gikogepoziwope.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461485/normal_6067c8f086244.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445745/normal_60590f52eb86c.pdfIn PDF document text
    • https://dofemavuxowag.weebly.com/uploads/1/3/0/7/130739836/natoginanepu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9f9bd9fa-00fe-4673-b34e-9a629881f524.filesusr.com/ugd/09273f_c2e2456283f74bfa8b402137f9569ab5.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/davawina/overview_forensic_investigation_report_into_steinhoff.pdfIn PDF document text
    • https://6974b9b2-fc2a-4e9b-9495-84ff65489eb7.filesusr.com/ugd/395280_0d27b305e66b498dad2ca8c9ac9ad5f6.pdf?index=trueIn PDF document text
    • https://ba428ff1-d53d-4eb5-bdb2-cc960067f420.filesusr.com/ugd/7041e4_10e7719cd85241d69fc77557a8651322.pdf?index=trueIn PDF document text
    • https://2a085669-a8dc-40eb-b1d3-71ea9d660f60.filesusr.com/ugd/cafc24_a90d3a8867f741ca822841f76aafd391.pdf?index=trueIn PDF document text
    • https://28f2c00a-638b-45ec-8848-4d649cb6aba9.filesusr.com/ugd/946f28_c219e5efe6054cfabdaeb08c2c5ab6b1.pdf?index=trueIn PDF document text
    • http://fugufaza.myartsonline.com/22393778140.pdfIn PDF document text
    • https://s3.amazonaws.com/wiwuxot/zakim.pdfIn PDF document text
    • https://a9750898-a066-404d-a796-54a2f5ad13bb.filesusr.com/ugd/60231a_590575db607147a2ac28281a3c72b83d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xupizewuxere/1643103110.pdfIn PDF document text
    • http://rovizomaguwex.atwebpages.com/sotagozafikujesuvazowet.pdfIn PDF document text
    • https://2cc12256-1025-444a-bacb-901a9f007bda.filesusr.com/ugd/d1fcfc_dbe951059a5346b8b2123892d7aecc2e.pdf?index=trueIn PDF document text
    • http://nokejufesuw.atwebpages.com/13423904094.pdfIn PDF document text
    • https://387a498e-9551-4239-9507-3183ba214552.filesusr.com/ugd/cd403b_370c074dbb5d47a999a185f1379e5b87.pdf?index=trueIn PDF document text
    • https://35057dd6-1d18-4acd-96c9-af3b7fddc7cd.filesusr.com/ugd/978dd5_fbcd8af4605e4db38971e12de090746b.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_off0000fcd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD0 5340 bytes
SHA-256: f599a0fa8da0e306b5fa0297780b1199de126c2cef6621ef1f2097de7f5eaf27
font_01_sfnt_off00010f0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F0D 10992 bytes
SHA-256: ff80d0e30650dc166f8910059ad2a38fa53f9eee2fb7c8fa54c73e5eb51eba90