Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b7891445ffa52e8…

MALICIOUS

PDF

76.7 KB Created: 2021-06-12 17:56:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0c58da1c3441cea7d56f0c22ca74b300 SHA-1: 8a9d9aaaf1b549f3e96e3550f577b3ba0c02bc9d SHA-256: 7b7891445ffa52e86cf43b12a9abc4b2516ab754244167868807ccd7771c04f0
186 Risk Score

Malware Insights

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

This PDF document was identified as malicious by multiple heuristics and an ML classifier, with ClamAV detecting it as a phishing trojan. It contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or phishing lure. The primary URL observed is https://krisoc.ru/pbw?utm_term=hospital+de+galdakao+especialidades, which likely serves as the initial entry point for the malicious activity.

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://krisoc.ru/pbw?utm_term=hospital+de+galdakao+especialidades PDF link annotation
    • https://bofuvuwowu.weebly.com/uploads/1/3/1/8/131856225/e9deb9bf04.pdfIn PDF document text
    • https://rufuwoja.weebly.com/uploads/1/3/4/7/134735928/74d9fd4.pdfIn PDF document text
    • https://nenejafaf.weebly.com/uploads/1/3/5/3/135393494/devosoloregog.pdfIn PDF document text
    • https://deminoki.weebly.com/uploads/1/3/5/3/135310913/lojux-dalixug-romur-powirajok.pdfIn PDF document text
    • https://kagifinozadobet.weebly.com/uploads/1/3/4/9/134902547/601223855e5d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373998/normal_60bffa9e04aad.pdfIn PDF document text
    • https://zapizurur.weebly.com/uploads/1/3/4/9/134900478/tudajatoduvifeg.pdfIn PDF document text
    • https://vigekajabaka.weebly.com/uploads/1/3/4/7/134708837/3630483.pdfIn PDF document text
    • https://tuzuratodaf.weebly.com/uploads/1/3/0/7/130738639/tuwevamemuba-rozodujaletelum.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424689/normal_5fdf719de7d30.pdfIn PDF document text
    • https://bazulezegit.weebly.com/uploads/1/3/4/3/134372971/f4a349f8f9ffd4e.pdfIn PDF document text
    • https://jofuzidud.weebly.com/uploads/1/3/4/8/134868871/3464008.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gogoporiwo.pbworks.com/w/file/fetch/144481287/poweporepipixedub.pdfIn PDF document text
    • http://sikovifif.pbworks.com/w/file/fetch/144476856/what_is_nikes_competitive_strategy.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db843cbb-d2c8-402e-bbf6-866d745d3773/how_do_you_answer_a_behavioral_nurse_interview_question.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01c9c7b3-2c8d-4461-a2a0-fe374d72ab91/kenneth_hagin_ministries_tulsa_oklahoma.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/89fc0dcd-9eb6-4c13-ad66-63f268456499/how_to_start_learning_british_sign_language.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf889d59-a51b-4e3c-afc2-87285b95debc/nolizodusudojupoboj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6fa98cc3-4e0b-4221-b136-0227654515d4/wezoj.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_off0000ea75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA75 5172 bytes
SHA-256: 5cf742858940b9477ccbc8eb6708875e494fd3dd7069a7daa3e507e5eafe03bf
font_01_sfnt_off0000fc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1F 12152 bytes
SHA-256: 7b428b4a432cec49178db4d889c089510d71aaa174583a550b74d9f59fcf7556