Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55dbb98383231e5…

MALICIOUS

PDF

77.3 KB Created: 2021-06-07 20:55:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: cc38939b6d55f4d6891225a71c099059 SHA-1: d5899ab6a9f1db5eeafe526517e14529b5a5f79e SHA-256: c55dbb98383231e50e7a0c7255b6cc490b56bb7731ce44c2d3488926a02269a1
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, suggesting a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://archism.ru/pbw?utm_term=data+structures+and+algorithm+analysis+in+java+textbook PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4446914/normal_5fe16be9760db.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366405/normal_60288edb4019f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382621/normal_5fe50645834cb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374379/normal_60ba67615e540.pdfIn PDF document text
    • https://sexaluweve.weebly.com/uploads/1/3/4/8/134854061/binewaku-garos-rinibosax-gorudanesad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404987/normal_606a65c19a63b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379377/normal_6001b94a3b214.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404953/normal_5fff48993e15b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413122/normal_605d70572da00.pdfIn PDF document text
    • https://liwifaxuje.weebly.com/uploads/1/3/0/8/130874244/maveb.pdfIn PDF document text
    • https://fuwanitawoge.weebly.com/uploads/1/3/4/4/134436239/ff62554788e3631.pdfIn PDF document text
    • https://mitivowa.weebly.com/uploads/1/3/1/6/131607237/e4976.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409248/normal_604fd75762977.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384851/normal_6017615758daa.pdfIn PDF document text
    • https://wejefagujevixow.weebly.com/uploads/1/3/4/4/134472609/xoxularitorapigug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372980/normal_6064f781c2b56.pdfIn PDF document text
    • https://tigasuzile.weebly.com/uploads/1/3/1/3/131379741/dufobedarazalo.pdfIn PDF document text
    • https://vutakajar.weebly.com/uploads/1/3/4/8/134896426/434514.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470035/normal_601474dfb78dd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://lekipirunezi.pbworks.com/w/file/fetch/144415035/97593780156.pdfIn PDF document text
    • http://pukagij.pbworks.com/f/49832923938.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_off0000eedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDD 5860 bytes
SHA-256: 58856e3d4c7ab9d57e1985326f1869140429387c4477a2414c0a66be8ce25db6
font_01_sfnt_off000102bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102BD 10832 bytes
SHA-256: d3084f3a161959bf2ae5557391ec3b9a7e08ae8ac073c1d3832cc5e338be1fd1