Malicious PDF — malware analysis report

Static analysis result for SHA-256 5cbd5bf2029e218e…

MALICIOUS

PDF

75.0 KB Created: 2021-02-25 14:37:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 18e0b145a9d6283b4c98fa6d604f26dd SHA-1: c00eab47089d81842af242a45fccb00bfe9ddfd5 SHA-256: 5cbd5bf2029e218e2047edb1d40016e643812af89f44bea2649d997d90baaa08
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by multiple heuristics and an ML classifier. It functions as a link farm, containing numerous external links to other PDF files hosted on disposable domains. The primary purpose appears to be SEO manipulation or distributing further malicious content, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ClamAV detection further supports its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://seumenha.ru/wb?keyword=cbse%20english%20grammar%20worksheets%20for%20grade%203%20pdf PDF link annotation
    • https://wawanuxofidote.weebly.com/uploads/1/3/0/7/130775818/6664312.pdfIn PDF document text
    • https://lubawefajisewo.weebly.com/uploads/1/3/4/4/134443910/losuxunololiwegub.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405430/normal_6027bfbd42380.pdfIn PDF document text
    • https://xeludelibiw.weebly.com/uploads/1/3/4/3/134371965/b0e18753c829e3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480399/normal_5ffe116278d38.pdfIn PDF document text
    • https://wumigativagulam.weebly.com/uploads/1/3/1/6/131637174/2119132.pdfIn PDF document text
    • https://wirupexulabajes.weebly.com/uploads/1/3/5/3/135322132/popubilina-ponuvanadijewe-wepafigup-tovab.pdfIn PDF document text
    • https://sepiximefajo.weebly.com/uploads/1/3/4/8/134849953/pozaxo.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414514/normal_5fcc38d08e9db.pdfIn PDF document text
    • https://xikuvisaduwobax.weebly.com/uploads/1/3/5/9/135962120/3aead740710374.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403563/normal_5fd3bd308a46d.pdfIn PDF document text
    • https://cdn.sqhk.co/vumulevezuf/iem8ghY/dilexi.pdfIn PDF document text
    • https://cdn.sqhk.co/kedezoge/UebYvuy/rolifiguvib.pdfIn PDF document text
    • https://cdn.sqhk.co/numorolele/iac8uhi/viperixebazil.pdfIn PDF document text
    • https://cdn.sqhk.co/mixubiki/hjd9Ojc/82701989224.pdfIn PDF document text
    • https://cdn.sqhk.co/fevivesuxofo/drjeDgj/crazy_taxi_2_apkpure.pdfIn PDF document text
    • https://cdn.sqhk.co/jozanafe/hd5d33Y/lisobigoza.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4468259/normal_5fcff49d08eba.pdfIn PDF document text
    • https://wemezixogasowed.weebly.com/uploads/1/3/1/6/131637562/5fc0a85.pdfIn PDF document text
    • https://cdn.sqhk.co/kasuvapexal/gdigo6M/baixar_videos_engracados_para_status_do_whatsapp.pdfIn PDF document text
    • https://puwawegolawibot.weebly.com/uploads/1/3/2/6/132682739/suwuvova_dowerisosulo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000e5b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B9 5820 bytes
SHA-256: cf5336878860ae93b5a62e7464a57ef97dee4b42b721a7212728a6cbd1733e60
font_01_sfnt_off0000f964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF964 10836 bytes
SHA-256: 1a8150fd2e377e10b406637f8db5dc29fd87bc4a303df4b7c3e4bc3c65772d3f