Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4149ed9e83686b9…

MALICIOUS

PDF

71.6 KB Created: 2021-06-09 10:47:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 1061569e9c0c19fc67584b195a52e114 SHA-1: 5625283147fc12457843c521f2ee6915414e82ad SHA-256: c4149ed9e83686b941951bccda135deafb1cba187f39e0cd6e5be25c92121c52
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 hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the presence of numerous external URLs and the PDF_SEO_LINK_FARM heuristic suggest the document's primary purpose is to redirect users to potentially malicious or ad-filled websites.

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://coretry.ru/pbw?utm_term=math+sheets+for+grade+4 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4465924/normal_600e9e7c378c3.pdfIn PDF document text
    • https://gulekizusivo.weebly.com/uploads/1/3/5/3/135392766/c40ee608245054d.pdfIn PDF document text
    • https://dotofufodil.weebly.com/uploads/1/3/5/3/135313806/7708509.pdfIn PDF document text
    • https://ziwagunu.weebly.com/uploads/1/3/4/8/134883986/bukomuxa.pdfIn PDF document text
    • https://jazujuwomukoti.weebly.com/uploads/1/3/4/6/134684961/1225544.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368242/normal_601bb2fe00ffe.pdfIn PDF document text
    • https://gilelofawabe.weebly.com/uploads/1/3/4/3/134370180/balifokum-sugov-zimapex.pdfIn PDF document text
    • https://wofibenozoga.weebly.com/uploads/1/3/5/3/135321696/7522716.pdfIn PDF document text
    • https://nojokubovurob.weebly.com/uploads/1/3/1/6/131606526/7149905.pdfIn PDF document text
    • https://paniselodo.weebly.com/uploads/1/3/5/9/135969975/zijojajidoxeredijowi.pdfIn PDF document text
    • https://tasuzifesuxad.weebly.com/uploads/1/3/7/5/137502252/balapegekaf_jifevojufofu_posuwi_pebovoraze.pdfIn PDF document text
    • https://ribifafugulif.weebly.com/uploads/1/3/4/6/134650062/nitawud.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384045/normal_6066fe64d504c.pdfIn PDF document text
    • https://kupefuvewugixo.weebly.com/uploads/1/3/4/8/134849821/gasuludazozi-medogusan.pdfIn PDF document text
    • https://mobonojijokatu.weebly.com/uploads/1/3/4/3/134320628/jesitataroviri.pdfIn PDF document text
    • https://menedufigejit.weebly.com/uploads/1/3/1/4/131482930/banusepevegokepoziv.pdfIn PDF document text
    • https://mulaxenowaw.weebly.com/uploads/1/3/4/8/134862071/witodabog_pinadoxe_zapolijasim.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/2cfb65f1-d960-4632-b44f-fe94021dda23/39292907428.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6be8aef-89b2-44d8-87bf-3944fb07b0d3/vitizagiwuzozor.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_off0000dbf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF0 5232 bytes
SHA-256: d20612a89e9bc72c4ac49b684426a57700799c35aa51f1732eb7bbfdbddf800b
font_01_sfnt_off0000edc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC9 10472 bytes
SHA-256: bcd1c93c45ee3befdbea7bf5f91b14f9aae7c1160d6bdb5ef57144404d08461d