Malicious PDF — malware analysis report

Static analysis result for SHA-256 9af4992e267a5f8c…

MALICIOUS

PDF

86.3 KB Created: 2021-05-30 22:03:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 89912af3f57c90c8d10ec5259a000777 SHA-1: d1abda031dab136775286554824b9e2c7fdf9b6a SHA-256: 9af4992e267a5f8c639729b923af3a2a21f37fe9175602a3563b0e6516f22542
214 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating it points to known malicious redirector infrastructure. The primary malicious URL identified is 'https://yafferge.ru/strik?utm_term=cpm+geometry+connections+answer+key+chapter+6'. The document body, though heavily obfuscated, suggests a lure related to 'Cpm geometry connections answer key chapter 6', likely to entice users to click the malicious links. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • 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
  • 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/strik?utm_term=cpm+geometry+connections+answer+key+chapter+6
    • https://cdn-cms.f-static.net/uploads/4378160/normal_600e6ef93ca17.pdf
    • https://cdn-cms.f-static.net/uploads/4476767/normal_5fe6559774607.pdf
    • https://cdn-cms.f-static.net/uploads/4378404/normal_60634244b28e2.pdf
    • https://static.s123-cdn-static.com/uploads/4393022/normal_5ffd9be65908c.pdf
    • https://cdn-cms.f-static.net/uploads/4401732/normal_60640ccd2d3a8.pdf
    • https://poxefapujo.weebly.com/uploads/1/3/5/3/135312596/285341.pdf
    • https://dexugagemer.weebly.com/uploads/1/3/4/7/134715037/3813724.pdf
    • https://static.s123-cdn-static.com/uploads/4444358/normal_5ff56c90633f1.pdf
    • https://birakegisepes.weebly.com/uploads/1/3/4/5/134597855/7b9f0.pdf
    • https://cdn-cms.f-static.net/uploads/4465935/normal_6033fd5379379.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/ad123e0a-59bf-471d-960f-d93c6a6e1127/sokanav.pdf
    • https://uploads.strikinglycdn.com/files/77958a1d-ab6b-438c-9619-2b925d560476/58994490199.pdf
    • https://uploads.strikinglycdn.com/files/d5da1497-e458-402f-8b62-5cf80a35b7a8/lodote.pdf
    • https://uploads.strikinglycdn.com/files/896fd908-4548-4a1b-a09d-a7439de34bf3/nogomu.pdf
    • https://uploads.strikinglycdn.com/files/d252e3cf-7a7b-4c7f-b577-a305b8fca7a4/zakofapej.pdf
    • https://uploads.strikinglycdn.com/files/04ca0a06-664e-46e0-97ea-38f2544d92c9/balancing_chemical_equations_worksheet_answers_1-20.pdf
    • https://uploads.strikinglycdn.com/files/cef121a4-a1f3-4882-83de-a7b31ba48f3d/hayward_salt_cell_warranty_replacement.pdf
    • https://uploads.strikinglycdn.com/files/e1b075c4-7f1a-4996-a359-a874ab4a399b/cyberpunk_2077_ps4_pro_patch_size.pdf
    • https://uploads.strikinglycdn.com/files/ecf8ad94-eca6-4534-9d7f-2cb9e1edfba3/18456031633.pdf
    • https://uploads.strikinglycdn.com/files/4153ff7e-115c-4462-922a-84222c7a4c60/302478941.pdf
    • 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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f992.bin
db9df56e9cea33d5176383683ab8273613f2c142101d261c0cd98ddebe588194		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF992 5632 bytes
font_01_sfnt_off00010cbb.bin
9f67dbf27f97a83f32dffc02f7fb898c6f6bacd0fbcfc63427f415fc9ed803bf		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBB 12108 bytes
font_02_sfnt_off00013645.bin
ab6a2d92c6195441154fe03e3add47570783810922a3b82dfc3833ffb97f5f96		 pdf-font-stream PDF embedded font (sfnt) at offset 0x13645 16072 bytes

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