Malicious PDF — malware analysis report

Static analysis result for SHA-256 c90debb1a6c7543d…

MALICIOUS

PDF

81.6 KB Created: 2021-05-29 23:53:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 011900708e32c5b833697977d1a28e3d SHA-1: 8065ade982e2b6fb151218e8ee952fb2fe3f592c SHA-256: c90debb1a6c7543d34aea7bb8dd1f2d419b98031cffb987cae88a35c71a995b3
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting, indicating a link farm designed to manipulate search engine results or direct users to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, but the PDF structure itself is indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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=coraline+book+online+graphic+novel PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4483855/normal_5feffc23313d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484143/normal_606e284c47718.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4383586/normal_5ff6c5b390afa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446761/normal_60542b34a7f13.pdfIn PDF document text
    • https://tuxativavowaz.weebly.com/uploads/1/3/1/4/131437956/xakokagimoxuda.pdfIn PDF document text
    • https://renunuvejo.weebly.com/uploads/1/3/4/7/134710344/ace2ef.pdfIn PDF document text
    • https://nazugawexavidi.weebly.com/uploads/1/3/4/6/134678572/a6eecf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444864/normal_6051ae779a728.pdfIn PDF document text
    • https://tatudikugox.weebly.com/uploads/1/3/4/7/134738012/datikenam.pdfIn PDF document text
    • https://soxigirotum.weebly.com/uploads/1/3/0/9/130969819/42bdea206d9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486965/normal_5fee2eb9c00fe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452382/normal_5fef7efe54c59.pdfIn PDF document text
    • https://dosoxikovere.weebly.com/uploads/1/3/0/9/130969917/91d08a923f6.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
    • https://uploads.strikinglycdn.com/files/9cf65659-837d-4638-bf10-dd7f40ab52d3/xogabugevomitogabunesere.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/38ef1d11-d24f-4f30-892a-996827eb6963/how_do_i_contact_chase_bank_by_email.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4f678212-ec07-47cb-abe6-6d9790e79746/what_is_introduction_of_exotic_species.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/40d5245c-f667-4fd7-a098-77e7f55fc5fc/dixik.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f5d9d62e-6c24-44d0-b060-cfa6b4d859f7/alexa_hindi_commands_list.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2afeb97b-1cfe-4c83-a108-5ae3b1db6ae3/97794921764.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/715956de-644f-40b7-b813-898a7758e5ee/will_fallout_4_new_vegas_mod_be_on_xbox_one.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bfec364e-d064-4dff-aaee-7163acd60877/jazz_piano_backing_tracks_free.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f50c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF50C 5012 bytes
SHA-256: 5b43c5bc82f9cbd39bfbb89f81ab19b09cccd4607f59fa5739486091d1cad098
font_01_sfnt_off00010605.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10605 10244 bytes
SHA-256: 0285e15f758d10b427e7ef462df5e95a78cc83d276ffc5fd4f7b1f8547f9d154
font_02_sfnt_off0001291e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1291E 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f