Malicious PDF — malware analysis report

Static analysis result for SHA-256 acb22f8e91053513…

MALICIOUS

PDF

77.5 KB Created: 2021-05-11 23:47:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: e87060adc7c445e3afea61c9e42901cb SHA-1: 92b4525e23dc1e6ab3c1f325dbb35e531d035065 SHA-256: acb22f8e91053513f9c036dee9b7b1dc59dcf6ba98989b3dbec9173591f9bd73
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 0.9991

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=can%2527t+install+realtek+hd+audio+manager PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4419626/normal_604b21246edef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426688/normal_6054084c249fa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421624/normal_6048ec17adb37.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413108/normal_6024f83f83cee.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385204/normal_5fff0c5b2c7b5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467586/normal_5fddf79bcb951.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482012/normal_6034c1119e5c4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465908/normal_60031ac4ca479.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411683/normal_60673ba73738b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367622/normal_600aad693293e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rabuxevemut.rf.gd/what_does_code_4_mean.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/561eae1b-4151-4f1e-b132-0fe7831c80bd/el_dador_de_recuerdos_online_pelisplus.pdfIn PDF document text
    • https://s3.amazonaws.com/rirusozo/jokiw.pdfIn PDF document text
    • http://vilolosukip.rf.gd/outline_the_budgeting_process_in_zambia.pdfIn PDF document text
    • https://s3.amazonaws.com/limepusotanal/31916672453.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0ce73d3-d8cd-476b-b8d4-de8fb7e78935/79287424390.pdfIn PDF document text
    • http://fatijilipoto.epizy.com/12066954885.pdfIn PDF document text
    • https://5d3a357a-25b2-4459-9cd8-210b235f7b36.filesusr.com/ugd/45e30f_0df739a01b614f23a7c810dc175e6f6a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/dbd3dc2c-2834-4136-915d-3a3767c2faac/is_there_such_thing_as_math_anxiety.pdfIn PDF document text
    • https://s3.amazonaws.com/jukezeluf/zexevabevedaregapuwa.pdfIn PDF document text
    • http://wovovaj.rf.gd/how_many_pages_is_the_twilight_book.pdfIn PDF document text
    • https://s3.amazonaws.com/livivuvuwugeb/32824759147.pdfIn PDF document text
    • http://turuduje.epizy.com/vimatutejumadoba.pdfIn PDF document text
    • https://43a2ba88-5de9-465b-b95f-6a4d82f2d06e.filesusr.com/ugd/dcbeda_2f33f704b5344814ba3e09f6183a8fd3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/leteraxewe/bimorafabo.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_off0000f09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09A 5240 bytes
SHA-256: 4eedf7af489491bd3ff3814c7dfb6a5a2cf70e01d19868e7d724916dde2e5977
font_01_sfnt_off00010242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10242 11104 bytes
SHA-256: 93c6bc4d4fcf9eae7782dcde3003d2fad5ba1618a1b5ae9a941a41d9d6f27942