Malicious PDF — malware analysis report

Static analysis result for SHA-256 a86cf7890763809d…

MALICIOUS

PDF

76.7 KB Created: 2021-06-12 00:48:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 108d38b4bf02c5be87a9dbb48d7fb9f1 SHA-1: b4dc0dd6a1a465612e100910a523f8b22d4a161e SHA-256: a86cf7890763809d91affa3997a6663cc7382b2f4e7ef3d27103290fd0bf0ee1
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 0.9995

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://vilenefex.ru/123?utm_term=adjectives+pdf+test PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4369495/normal_5ff24a3da547f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447278/normal_60155663e2700.pdfIn PDF document text
    • https://pilimulifedi.weebly.com/uploads/1/3/4/8/134852071/6678091.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369660/normal_606e210544077.pdfIn PDF document text
    • https://tezilejesitox.weebly.com/uploads/1/3/1/1/131163634/xojere-muxoxawa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415292/normal_60c2e755175eb.pdfIn PDF document text
    • https://sewimumox.weebly.com/uploads/1/3/4/6/134668968/1050335.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4491673/normal_5ff5bedb86198.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488560/normal_5fe7833b322a8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495860/normal_60503040ec10a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373755/normal_604f58897d4d9.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://vazufatar.pbworks.com/f/92921416907.pdfIn PDF document text
    • http://fotikeralo.pbworks.com/w/file/fetch/144825075/63461609611.pdfIn PDF document text
    • http://kuzimotum.pbworks.com/w/file/fetch/144553083/61818563992.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ff828d14-fc02-4840-a5db-a38d7453bcc1/what_is_the_principal_difference_between_a_strong_and_weak_acid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/977580d7-b4ad-45b6-84b3-2a51fca31319/59092884791.pdfIn PDF document text
    • http://nolumemonip.pbworks.com/w/file/fetch/144512646/novela_el_cuerpo_del_deseo_capitulo_35.pdfIn PDF document text
    • http://moxulolo.pbworks.com/f/74165185051.pdfIn PDF document text
    • http://niluputevi.pbworks.com/f/57729106078.pdfIn PDF document text
    • http://jumedew.pbworks.com/w/file/fetch/145136211/moxetabi.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC66 4508 bytes
SHA-256: c2d57b66869a5a35fc79ba8a48d73145f5aa0ec8c45cd8277d605a2898e23fa1
font_01_sfnt_off0000dbd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD5 11276 bytes
SHA-256: 7aaee84adfe9d68ac311376e4288212056f81b1e1ae21b4105e3ca97ee775f71
font_02_sfnt_off0001025e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1025E 16080 bytes
SHA-256: bf2bb651642035a19e1b8bf5dc55c4db7948913289cd11d1f66f0c65c0fed8c7
font_03_sfnt_off00011720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11720 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361