Malicious PDF — malware analysis report

Static analysis result for SHA-256 924d6bdbca934a09…

MALICIOUS

PDF

75.2 KB Created: 2021-02-14 12:49:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-03
MD5: 74965bdc3712220d008b75dab40b2ee4 SHA-1: 38740ca6d083e84e4eba7f7b9af79fb8538548fd SHA-256: 924d6bdbca934a092c565556f4247589b458ec8c4043557e5236aaf71f4ff4a4
154 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics, including a critical alert for a PDF redirector link to 'yafferge.ru'. The ML classifier also strongly flagged the PDF. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often abused to create malicious PDFs. The primary IOC is the malicious URL, which is likely used to deliver a secondary payload or redirect to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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://yafferge.ru/aws?utm_term=beautiful+girl+babies+images In PDF document text
    • https://cdn.sqhk.co/nemalerute/Hjbjcuv/47297231260.pdfIn PDF document text
    • https://cdn.sqhk.co/laruxibut/qm4if1j/68396962571.pdfIn PDF document text
    • http://mofawab.66ghz.com/types_of_refractive_error.pdfIn PDF document text
    • https://cdn.sqhk.co/jutafegobexe/SFr2ujf/1006880461.pdfIn PDF document text
    • https://cdn.sqhk.co/mepofazobi/fyjifja/1378011775.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457572/normal_5ff67472c2cc0.pdfIn PDF document text
    • https://cdn.sqhk.co/jugemito/iifidih/inside_out_coaching_book_review.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370089/normal_5feb8fcf0ff70.pdfIn PDF document text
    • https://cdn.sqhk.co/xuxodokoju/379l8z0/sugawazi.pdfIn PDF document text
    • https://cdn.sqhk.co/gunonutib/aEqIQDt/9897301695.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
    • https://s3.amazonaws.com/daselex/breaker_panel_directory_template.pdfIn PDF document text
    • https://s3.amazonaws.com/faduxodiwo/edwards_river_fishing_report_2019.pdfIn PDF document text
    • http://lodabaximuxulul.epizy.com/coffee_meets_bagel_apk.pdfIn PDF document text
    • http://bonitadobizaw.epizy.com/piriformis_sciatica_stretches.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2A 4940 bytes
SHA-256: 373e1bd6b606392e0b0b49da0e510af7463e50d6240be7f5c74c9925184c9df4
font_01_sfnt_off0000edfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFA 10556 bytes
SHA-256: 376e5c89e476e82d4cdb77355435d0e68c1ad99304ed9f79d6cda9295572e28e
font_02_sfnt_off000111be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111BE 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34

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