Malicious PDF — malware analysis report

Static analysis result for SHA-256 c97550b82899f077…

MALICIOUS

PDF

88.4 KB Created: 2021-05-23 09:04:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 3e9beee7d1376276f8a4edef6cb67c13 SHA-1: bb74c250465e4628f190e0248e4364bb54ecc652 SHA-256: c97550b82899f077f3fc51a058518db25110288eebac27d2432f60b5ea7c9d7b
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to other PDF files hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were directly extracted, the nature of the link farm suggests it could be used to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://golowaki.ru/strik?utm_term=public+finance+and+taxation+pdf+notes PDF link annotation
    • https://xovesoxak.weebly.com/uploads/1/3/0/8/130813458/7680805.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449421/normal_601a07fe89565.pdfIn PDF document text
    • https://kitozegukelod.weebly.com/uploads/1/3/6/0/136056839/rupelakib_petiwasapi_romojivumuv.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383327/normal_603e97926315a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387826/normal_6047d95eebd34.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388424/normal_5fd795a5e8f26.pdfIn PDF document text
    • https://jafekubu.weebly.com/uploads/1/3/0/8/130814731/sagini_lirep.pdfIn PDF document text
    • https://zefijevizo.weebly.com/uploads/1/3/2/3/132302816/f715d96.pdfIn PDF document text
    • https://nozodipipagim.weebly.com/uploads/1/3/1/4/131438171/xosugab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393346/normal_5fd2876cb6fe6.pdfIn PDF document text
    • https://mofesotuju.weebly.com/uploads/1/3/4/7/134712265/dafar.pdfIn PDF document text
    • https://mutobituza.weebly.com/uploads/1/3/4/3/134352411/81f6a13b9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366676/normal_6041b327df1bb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412768/normal_6013c61c3d00b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481513/normal_601dd1caf2e77.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/57aacfd7-9bc3-40bf-bf33-d06cbb333e80/69884123546.pdfIn PDF document text
    • https://s3.amazonaws.com/moduxanakuri/is_lord_of_the_rings_real_4k.pdfIn PDF document text
    • https://s3.amazonaws.com/rumezo/how_to_respond_to_parental_alienation.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/370e31ac-b2a1-44da-9051-9f4abafcb2d4/tajine_tefal_livre_recette.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/69fc88fa-ee09-41d4-8707-5704613d98f0/segusapok.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/88e6d129-b821-4690-90f8-bc024f0603ad/wisavigulosu.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_off000118fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118FB 5260 bytes
SHA-256: bb2239157302f6c0ed8adcd8e32c691231cd57ff2d4100186d52cf55774af058
font_01_sfnt_off00012afd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AFD 11544 bytes
SHA-256: bbff7912137fccae79c06ddbf21d17c2b95b093ba89ac7be48b4259316662c31