Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5caf17c7bae781…

MALICIOUS

PDF

91.4 KB Created: 2021-04-05 04:43:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3ac6a079807459a06ebd15e8d5c7271b SHA-1: 7c4b3a16adda5c667e8a068a2d3e8350219028ba SHA-256: 4b5caf17c7bae781126e207388fb7f7db167eabfe12d58caafe6baacdb527bc4
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are SEO-themed and point to other PDFs, indicating a link farm or phishing operation. The ClamAV detection and ML classifier strongly suggest malicious intent. The embedded URLs are likely used to redirect users to malicious sites for 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://resalured.ru/wix?keyword=thinking+in+systems+a+primer+pdf+espa%25C3%25B1ol
    • https://cdn.sqhk.co/zizaratijiga/iifhhD6/m1_prepaid_to_postpaid.pdf
    • https://cdn-cms.f-static.net/uploads/4409113/normal_5fe6a36dd02ef.pdf
    • https://cdn.sqhk.co/gukisafuw/bSoEXHO/90307017665.pdf
    • https://kekuzisalan.weebly.com/uploads/1/3/0/8/130813403/f63b74b20.pdf
    • https://cdn.sqhk.co/rijunawep/Nhc5jMU/28418703984.pdf
    • https://cdn-cms.f-static.net/uploads/4495973/normal_606826c65fe73.pdf
    • https://susakatevasek.weebly.com/uploads/1/3/4/8/134871092/8019013.pdf
    • https://cdn.sqhk.co/jimavidozeze/ZSP9iia/46059846618.pdf
    • https://cdn.sqhk.co/ranemagesoga/gvjaFhc/wosurojebi.pdf
    • https://durafozo.weebly.com/uploads/1/3/0/7/130740533/noxuvotamutamusu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • http://sixofiwezuxowa.epizy.com/77200363723.pdf
    • http://sekijipaladi.epizy.com/vande_mataram_original_song.pdf
    • http://garurake.rf.gd/data_presentation_and_analysis_in_qualitative_research.pdf
    • https://5f8b0e40-2141-4341-98ab-6145db4b8156.filesusr.com/ugd/2072cd_9b361df73ab44a1aa3be12016ff1c4c3.pdf?index=true
    • https://59e5a08b-0d8d-455f-a3a7-35a3b781ab3e.filesusr.com/ugd/784815_987161d949ec4512b818348b9442044b.pdf?index=true
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011726.bin
a061e850d8101725cce747c368843f01246f677adc8200b80ad63765c83cae49
pdf-font-stream PDF embedded font (sfnt) at offset 0x11726 5568 bytes
font_01_sfnt_off0001299f.bin
40427b0b9e7656cc83795870c19801635dfe35d95b21bc83206aaca6537c12bd
pdf-font-stream PDF embedded font (sfnt) at offset 0x1299F 11712 bytes
font_02_sfnt_off0001504e.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x1504E 4324 bytes