Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c79899083d0308c…

MALICIOUS

PDF

78.7 KB Created: 2021-04-03 01:24:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: a322c63ef05ac9e04cd1750485d1ba77 SHA-1: b17e73ae0a076fd0b29cc7326ed06f0a6b8a3949 SHA-256: 7c79899083d0308cbb4cf22d13270030c35d8dd6dc60a4ae2d7dad7536a3af99
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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://jacksth.ru/strik?utm_term=asus+rt-ac87u+firmware+merlin PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4487005/normal_6000a0068c6f4.pdfIn PDF document text
    • https://gegoviboz.weebly.com/uploads/1/3/4/8/134876631/pifajem.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382192/normal_5fd7eecd59433.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495400/normal_6052168e3d298.pdfIn PDF document text
    • https://sozivaxuzafuzi.weebly.com/uploads/1/3/1/8/131856435/sekudu_felixavumigu_falewetibutefa_ronusugamutu.pdfIn PDF document text
    • http://idealslimitalia-official.site/are_hybrid_water_heaters_worth_it38jo3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476783/normal_603e0915ceed7.pdfIn PDF document text
    • https://jewaxesototipa.weebly.com/uploads/1/3/5/3/135326518/356c1bf861.pdfIn PDF document text
    • http://stav-games.ru/kbc_answer_2018_app8mop8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4383572/normal_5ffcfc27e7088.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/paropabaru/rekajozo.pdfIn PDF document text
    • https://587b455d-cc79-4428-8e80-a8b75ce23bca.filesusr.com/ugd/021ec8_168f510575bf44819ff298482f302c83.pdf?index=trueIn PDF document text
    • https://85d2c5a2-fc31-4f76-86b4-4ebe2abe2bf4.filesusr.com/ugd/a8cc01_1e904131bbdd4ad481a923afbfeed8ae.pdf?index=trueIn PDF document text
    • https://d6a293f2-6876-493d-91b7-c13182b05023.filesusr.com/ugd/bcaa7e_d7b2f638e896477c9204d319312fe4e8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/panalipolifod/interior_design_certificate_course_in_kenya.pdfIn PDF document text
    • https://7e073981-ad1c-4081-8dc0-76946ba36063.filesusr.com/ugd/c4f63d_ac057ced676a4e348e2ac9af7fa7c806.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fukepez/12306274319.pdfIn PDF document text
    • https://s3.amazonaws.com/tisegovofu/99916184987.pdfIn PDF document text
    • https://53ee2ee6-42da-4c96-954f-60f726bc8d53.filesusr.com/ugd/de2744_30c3f4d18d4b4d64aa5cae038138fe61.pdf?index=trueIn PDF document text
    • https://5e20aa6b-77ef-4f11-9344-5454fb7c649c.filesusr.com/ugd/fb3aa9_ec328fe178b14abf9ea613873688cc44.pdf?index=trueIn PDF document text
    • https://31e64076-56b3-4e53-9780-179364fbad2f.filesusr.com/ugd/d8d3cb_3afc922eb47f4294a486b32b8f690a8a.pdf?index=trueIn PDF document text
    • https://81da701b-0f85-48f9-9040-0f88ba79a05f.filesusr.com/ugd/bf07b1_3e62acbaa60a4a48b113600f455c518e.pdf?index=trueIn 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_off0000f639.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF639 5412 bytes
SHA-256: 0288194e3b632a85ff222a448b92c7c3fc87421461025f41784dba247f8d3271
font_01_sfnt_off000108aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AA 11044 bytes
SHA-256: 518d566ab616c706fba812e2c80cc9468e044bbc749bc98fe5e30928f64ef410