Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbb420445192363d…

MALICIOUS

PDF

79.0 KB Created: 2021-05-31 14:25:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: fa39c71b3d775f40d7512bfaf531bf6f SHA-1: e375faf4a326569190ad28709fe0100a3faa6f20 SHA-256: dbb420445192363d9f8fc0f88cb9dd1de7c35c8efe2e538d336f68e1698ce822
126 Risk Score

Malware Insights

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

The PDF document is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to disposable hosting and are used in a link farm, suggesting a phishing or malware distribution attempt. The document body, though heavily obfuscated, appears to be a lure for a free textbook download, which is a common social engineering tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://leonvi.ru/strik?utm_term=vishram+singh+neuroanatomy+4th+edition+pdf+free+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4495058/normal_6003bdc602515.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4423188/normal_5fef3c7ad3e87.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459788/normal_5feb7c59b151c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453532/normal_604e4b5d706c8.pdfIn PDF document text
    • https://bekaxerovesujes.weebly.com/uploads/1/3/4/8/134856890/435ee744d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450034/normal_601bdde91d409.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368989/normal_5fc5841ec85c5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379603/normal_60478efa45301.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448984/normal_6022e22e3a8aa.pdfIn PDF document text
    • https://jilazokezabise.weebly.com/uploads/1/3/5/2/135296918/dexebuma.pdfIn PDF document text
    • https://wivirupi.weebly.com/uploads/1/3/4/6/134666213/ximenaxedibejibef.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4426424/normal_60afed9701a39.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369640/normal_600e96315fe36.pdfIn PDF document text
    • https://senuwisaf.weebly.com/uploads/1/3/4/0/134018119/pamifinogu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497082/normal_601a6fadd74ab.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366015/normal_5fcad24cd2a9b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455195/normal_6058b5cabe0b3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406782/normal_5ff50f8218928.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b7f3b2b0-77cf-428b-8cb7-7fe651d46119/borderline_personality_disorder_and_schizophrenia_similarities.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c3464bf-a64a-497e-b628-2a4a1e843985/the_boy_in_striped_pajamas_summary_chapter_8.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f16e037-d644-4c1d-9424-24c77121e484/how_to_formulate_questions_in_qualitative_research.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/753d0ce1-8e9a-43e4-a74f-c2469d8f140b/gazumalojusekox.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f48d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF48D 5700 bytes
SHA-256: 47f8117a81623332d7e9f0e80c767c10b64ecad821f04ed34fca528e4b6f2981
font_01_sfnt_off000107eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EB 11168 bytes
SHA-256: 97855cc100193fac87780c522a7dd04a638a89dae274d123832ed0e0f5400274