Malicious PDF — malware analysis report

Static analysis result for SHA-256 851cd1d19fe4eb78…

MALICIOUS

PDF

72.5 KB Created: 2021-02-11 17:44:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 498a8a4599fa843dc82e9d93101fddbb SHA-1: 1621ed13e2b0d632e67dfda788599f9c055c98fb SHA-256: 851cd1d19fe4eb782ac34af5c47670e38cf3747f81f1df28d82739267019485a
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, indicating a link farm or SEO spam operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The embedded URLs are the primary indicators of compromise, directing users to potentially harmful content.

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://seumenha.ru/wb?keyword=sociology%20summary%20pdf PDF link annotation
    • https://tukumexof.weebly.com/uploads/1/3/4/7/134721389/nidifap.pdfIn PDF document text
    • https://cdn.sqhk.co/virurewev/idhd3hc/jobemijumowilupetive.pdfIn PDF document text
    • https://cdn.sqhk.co/jipogidara/fiiihle/final_fantasy_14_ivalice.pdfIn PDF document text
    • http://wavepolabipal.22web.org/xerawi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417813/normal_5ffb2fece4565.pdfIn PDF document text
    • https://dirifulezidume.weebly.com/uploads/1/3/2/7/132740871/xadegabobe_sekol.pdfIn PDF document text
    • https://kotutoxegaru.weebly.com/uploads/1/3/2/6/132695780/todufut.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447431/normal_5fd173dec41cf.pdfIn PDF document text
    • https://jusodizepo.weebly.com/uploads/1/3/1/0/131070216/ea90eeb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393346/normal_5feee326d19f7.pdfIn PDF document text
    • https://pemogele.weebly.com/uploads/1/3/5/3/135324676/dc3446e18a551c.pdfIn PDF document text
    • http://lupokixez.22web.org/jorog.pdfIn PDF document text
    • https://rujijixagav.weebly.com/uploads/1/3/1/3/131383475/8c142.pdfIn PDF document text
    • https://tipowunukal.weebly.com/uploads/1/3/4/3/134355136/4c35d2106a4.pdfIn PDF document text
    • http://xenipufuk.22web.org/binobeberanabuku.pdfIn PDF document text
    • https://joxejiduzimomad.weebly.com/uploads/1/3/1/3/131383973/dukasol-digal.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sugosabogakeg.rf.gd/83781941547.pdfIn PDF document text
    • http://sekupudim.rf.gd/financial_reporting_manual_2018.pdfIn PDF document text
    • http://jufebiwewizeza.rf.gd/jiridufidelefapoxexebi.pdfIn PDF document text
    • http://zatugawaxevi.rf.gd/mubazegemijipojadetewet.pdfIn PDF document text
    • http://tupomomi.rf.gd/strengths_and_weaknesses_questions_and_answers.pdfIn PDF document text
    • http://nidawijonag.rf.gd/sadedabezetiwasutuxisu.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_off0000de43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE43 5680 bytes
SHA-256: 03ee0cb385ddd9c5deb47e389bd4d743c24bd4df002fd9b4461e97fb9bf2a1d0
font_01_sfnt_off0000f192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF192 10432 bytes
SHA-256: 8915278cfc798cd103ef6bf929d94d0450ceffc9c5ad40fd68b8059f4763f008