Malicious PDF — malware analysis report

Static analysis result for SHA-256 810296f06b3b98dc…

MALICIOUS

PDF

85.3 KB Created: 2021-06-03 22:30:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: aea40f8a17b0e0d8df19e6876cedaacf SHA-1: 67cc7b9cfe9a3b9af5fd73e0c6ced759aae110a3 SHA-256: 810296f06b3b98dc5b7df65c4ea46b7fe7f5c346165352a40d6d39e954bb9040
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a large number of external links, many pointing to disposable domains and potentially benign-looking PDF files, characteristic of a link farm designed to obscure malicious intent. One of the primary external links is to 'jacksth.ru', which is likely part of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/123?utm_term=caffe2+android+demo PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4368767/normal_5fcc7efb7e49a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366360/normal_60315edad7398.pdfIn PDF document text
    • https://kedepojab.weebly.com/uploads/1/3/0/7/130739947/tiripibifeve.pdfIn PDF document text
    • https://penopetidurip.weebly.com/uploads/1/3/2/8/132815040/levasupuge.pdfIn PDF document text
    • https://xixusumer.weebly.com/uploads/1/3/0/8/130814933/3513811.pdfIn PDF document text
    • https://jojawetoterul.weebly.com/uploads/1/3/4/4/134404105/23f45127351a.pdfIn PDF document text
    • https://zotaboxobur.weebly.com/uploads/1/3/6/0/136091523/dowegepa-relusekapu-zuvilewupa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382187/normal_60257b0abc121.pdfIn PDF document text
    • https://tozubovudifudi.weebly.com/uploads/1/3/5/9/135973827/d30c36fa.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4466379/normal_5ffb7c623865b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421061/normal_5ffe4b2d24b7a.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4467950/normal_60b264a37ff08.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480753/normal_5fcb089991a1b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446645/normal_603724c72711b.pdfIn PDF document text
    • https://kuvovoturuja.weebly.com/uploads/1/3/5/3/135322548/4375846.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377101/normal_5fef523992855.pdfIn PDF document text
    • https://boxomuti.weebly.com/uploads/1/3/4/0/134016719/4407493.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jiboduxoguv.pbworks.com/f/lasoxu.pdfIn PDF document text
    • http://kigemulu.pbworks.com/f/isaac_physics_answers_efficiency.pdfIn PDF document text
    • http://kiletejude.pbworks.com/f/private_limited_company_in_ethiopia_amharic.pdfIn PDF document text
    • http://rimikupababo.pbworks.com/w/file/fetch/144554784/pawewugekunifuxufumu.pdfIn PDF document text
    • http://siwuromo.pbworks.com/w/file/fetch/144425460/ejercicios_de_razonamiento_matematico_resueltos_para_bachillerato.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_off00010d14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D14 4880 bytes
SHA-256: 7cb6402cb36ac8df5c145430ce24254b481a2f44b9b9a947763449221b94f45e
font_01_sfnt_off00011d99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D99 12620 bytes
SHA-256: e2a37dcfd677e491cd1bc198372e054fa3aefc1ee54c4ae58dbc7769e52a2aee