Malicious PDF — malware analysis report

Static analysis result for SHA-256 66a8719a88513d9d…

MALICIOUS

PDF

86.7 KB Created: 2021-04-01 19:56:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 8a4af90200722d0ff7ed23c78e2d9fa7 SHA-1: 269fd82768395704b6fe27dbe2e1f0f90b999872 SHA-256: 66a8719a88513d9d593054400e6e0541c2b89ba4f5f9391c758dfd7edcadfb7f
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous embedded URLs, many pointing to disposable hosting and acting as a link farm, with one prominent URL being https://bologen.ru/strik. This suggests the document's primary purpose is to redirect users to potentially malicious sites, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://bologen.ru/strik?utm_term=marine+corps+martial+arts+program+instructors+trainers+course+record PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4413713/normal_6047ebd38bae2.pdfIn PDF document text
    • https://cdn.sqhk.co/surodamiz/daiifCa/dog_balls_amazon.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479236/normal_6024b67b95e78.pdfIn PDF document text
    • http://teaitalis.space/xidifemop5zo3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471464/normal_601ba89b5225f.pdfIn PDF document text
    • https://cdn.sqhk.co/jarogofef/bhighbA/55467935537.pdfIn PDF document text
    • https://cdn.sqhk.co/vedasukuki/jfGdJjf/sites_in_vr_app_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490269/normal_5ff0ee3400177.pdfIn PDF document text
    • https://cdn.sqhk.co/zomulusiku/gIYjiUU/check_my_android_for_spyware.pdfIn PDF document text
    • http://my-favshope.online/tippmann_a-5_stockgjbaq.pdfIn PDF document text
    • http://domavera.ru/10209046191d4h3e.pdfIn PDF document text
    • https://cdn.sqhk.co/nonuripot/eJfgf1q/likir.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/fcb93568-e556-4870-8181-4c1280fcfcf0/6929217289.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dde482d1-710a-4b84-8f99-5f3a72716aed/mofusitixowuzomek.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a7d1305c-aedb-48d8-8f10-cecba028ff8c/rupunoxomugivomolosu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0bb8d7d-1647-4b1e-ab05-e9f1d1c3466d/remalok.pdfIn PDF document text
    • https://s3.amazonaws.com/desekusoxi/46112513247.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d4b8c46e-71e8-4b88-a6bd-762975b314c4/how_to_oil_singer_heavy_duty.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/df7f22b6-2f59-47c5-8a74-bc2c5b20fd5f/relational_database_management_system_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dc182296-51f0-421d-9bc2-861c34ec1fd1/renexed.pdfIn PDF document text
    • https://s3.amazonaws.com/falejogajir/becoming_a_teacher_11th_edition.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_off00010629.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10629 5280 bytes
SHA-256: b85d6bc258d20648c5e90648d92e8bdd9e1141c1cb59aa61c94976a415e63a30
font_01_sfnt_off000117fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117FA 11472 bytes
SHA-256: afd007d1b0f92d1acff512f7dec60b8df631050bc4707028999a381222dbd898
font_02_sfnt_off00013ec9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EC9 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e