Malicious PDF — malware analysis report

Static analysis result for SHA-256 51a5ce9e19bd217d…

MALICIOUS

PDF

85.4 KB Created: 2021-03-15 22:23:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: ece50a1c808fe6ac926e5b6a62d8bd74 SHA-1: 226dd875a7cf45b1a1ea233cc4f623eb4c8ad2ac SHA-256: 51a5ce9e19bd217d5188cfc7bb79b0624732157c7ed5db0ac99345285e300c4b
186 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including PDF_SEO_LINK_FARM and ML_NYX_PDF_MALICIOUS, indicating a high likelihood of malicious intent. It contains numerous external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports this assessment. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://druttle.ru/strik?utm_term=cochlear+kanso+2+sound+processor PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4384144/normal_6048f91b33d39.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405197/normal_602a3d62d935f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377401/normal_5fd99595ec9e3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453560/normal_5fc873adc5edc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485927/normal_600e2f6065172.pdfIn PDF document text
    • https://cdn.sqhk.co/lotidonita/tO4txhc/6325533216.pdfIn PDF document text
    • https://cdn.sqhk.co/bebuvasipen/heicYhe/kogokekiwerinasid.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://xafepabofi.epizy.com/what_is_skim_milk_on_21_day_fix.pdfIn PDF document text
    • https://b9a4c3d6-4ccf-4d04-9b0f-c2e9c357e15d.filesusr.com/ugd/e5cbe5_ac44513e6cc344919f0ae307a4a6c76b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wulagisi/vicks_starry_night_humidifier_green.pdfIn PDF document text
    • https://s3.amazonaws.com/wukevirenesu/asm_handbook_volume._6_welding_brazing_10th_ed.pdfIn PDF document text
    • http://zokusopejexumub.rf.gd/change_apple_billing_information_to_none.pdfIn PDF document text
    • http://kasaxamaburabuz.epizy.com/sogudodafetorexu.pdfIn PDF document text
    • https://413f70bc-0247-4a04-a3fc-eabb14e2b93f.filesusr.com/ugd/f18ee6_3a3b4cddfa3c4ad98197d88efa04ded5.pdf?index=trueIn PDF document text
    • http://nufejubonuviwo.epizy.com/general_partnership_agreement.pdfIn PDF document text
    • http://vedezaduxi.epizy.com/80701244505.pdfIn PDF document text
    • https://1bf92926-22d0-44a1-94fb-b51843c41cd5.filesusr.com/ugd/762c1a_a318d8e4e5c141188ef72568d6f30ac0.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ffab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAB 5132 bytes
SHA-256: 906846f74f17cb74200e695b2c74e9e7bd16d2d23b094e50cb9ff03b9b5f9503
font_01_sfnt_off0001110a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1110A 11664 bytes
SHA-256: 55fd40f7ab4cfe0394db97659e9fb500a276e445353174275a9f1f8b50531137
font_02_sfnt_off0001387f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1387F 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176

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