Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c99379d3711019…

MALICIOUS

PDF

91.7 KB Created: 2021-06-01 11:06:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 7f3d2d2e5ccab28f4a7ed34234f91d03 SHA-1: b0cfd48c03fd8d579c63f8414ab09a677eaa3b77 SHA-256: 51c99379d37110191f9417b9db2d54136789a6394f799c38407462bfeca79e31
186 Risk Score

Malware Insights

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

This PDF document functions as a link farm, directing users to numerous external websites, including a suspicious URL related to 'driving school ielts listening answers'. The presence of multiple external links and the detection by ClamAV as 'Pdf.Phishing.Trojan' strongly indicate a phishing or SEO spam campaign. No scripts were extracted, but the document's structure and embedded URLs suggest it's designed to redirect users to malicious or deceptive 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://inwebjor.ru/pbw?utm_term=driving+school+ielts+listening+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4390642/normal_602c84714992e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391893/normal_602d95805b7d4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371523/normal_5ffcd1c85b699.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446036/normal_6013bee4561f0.pdfIn PDF document text
    • https://vokewubepil.weebly.com/uploads/1/3/4/4/134443825/firojawinanu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383165/normal_601474db52ab7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416659/normal_605f39acd52fb.pdfIn PDF document text
    • https://fidejilajusaxe.weebly.com/uploads/1/3/4/3/134363993/9907218.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378621/normal_5fcea5d5d460d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497095/normal_60404f68c32e1.pdfIn PDF document text
    • https://luvupomadimudux.weebly.com/uploads/1/3/4/3/134350134/jemibexiguv_gudetake_jipoleniwopod_xebokaxudiwelox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485457/normal_606bd21d6a752.pdfIn PDF document text
    • https://rozomibevepozif.weebly.com/uploads/1/3/0/7/130775668/8466661.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476122/normal_6006d5784ce34.pdfIn PDF document text
    • https://depoferi.weebly.com/uploads/1/3/4/4/134445349/jomofumesalonobapomu.pdfIn PDF document text
    • https://pusakinadolelu.weebly.com/uploads/1/3/2/6/132682110/3039935.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426972/normal_601972f8acffb.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4505102/normal_60b1e8d88bafa.pdfIn PDF document text
    • https://fesimubigezati.weebly.com/uploads/1/3/4/5/134515628/jupokogomen.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487416/normal_604cc4abebd7a.pdfIn PDF document text
    • https://gugedawojovo.weebly.com/uploads/1/3/4/5/134590720/b55e6b5a.pdfIn PDF document text
    • https://tefuxaforubexo.weebly.com/uploads/1/3/4/4/134446539/tomep.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_off00011b5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B5D 5212 bytes
SHA-256: 226e48d3454d3ecc579f930a419d70f80b80f498916eb0676654da8e0cb438e4
font_01_sfnt_off00012d36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D36 24200 bytes
SHA-256: c5cc79408a5c48fcd9d6584de5367464ddda59d589dc070faef972c74b6812c1