Malicious PDF — malware analysis report

Static analysis result for SHA-256 a228b9f7fd70b951…

MALICIOUS

PDF

68.7 KB Created: 2020-12-14 13:20:16 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8f5bc57af2a74918b7720eb223e59c7f SHA-1: 1f6ffd1dcda5a5cc6d490d892b82895f76e357be SHA-256: a228b9f7fd70b9513805060f60e4bf8d32fa2c5cf1f484f810238651d457e587
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious content. It contains a large number of external links, many of which are likely part of a link farm designed to direct users to malicious sites, as suggested by the PDF_SEO_LINK_FARM heuristic. The embedded URL `https://traffine.ru/strik?utm_term=blackfoot+mental+institution` is a primary indicator of malicious intent, likely serving as a redirector or landing page for further attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://traffine.ru/strik?utm_term=blackfoot+mental+institution
    • https://mejodedasebedo.weebly.com/uploads/1/3/4/7/134725949/55e96f978.pdf
    • https://static.s123-cdn-static.com/uploads/4445534/normal_5fd05642cbf75.pdf
    • https://cdn-cms.f-static.net/uploads/4408582/normal_5fb3d88bd8bb8.pdf
    • https://cdn-cms.f-static.net/uploads/4365591/normal_5f89810e47fff.pdf
    • https://cdn-cms.f-static.net/uploads/4464739/normal_5fd64a05e4e45.pdf
    • https://cdn-cms.f-static.net/uploads/4366645/normal_5f8740b6bfc4c.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/muxozuvalubi/reading_practice_worksheets_8th_grade.pdf
    • https://s3.amazonaws.com/fonibinaraj/design_doll_4._0_0._9_cracked.pdf
    • https://uploads.strikinglycdn.com/files/863de514-69ca-43f8-9209-850b5f287144/custom_order_maid_3d2_english.pdf
    • https://s3.amazonaws.com/mujesogi/human_body_systems_worksheets_answers.pdf
    • https://s3.amazonaws.com/sefiwegegagu/16926092686.pdf
    • https://s3.amazonaws.com/nalifij/wuzalan.pdf
    • https://s3.amazonaws.com/vabemavuputenif/18977418301.pdf
    • https://uploads.strikinglycdn.com/files/c519513c-5771-42aa-be2f-63da4d2c0ac0/chrysler_pacifica_reliability_consumer_reports.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d170.bin
cd2b147023978c324b739a823e30080740dce84aebd20d9f15320efb379ff6e5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD170 5044 bytes
font_01_sfnt_off0000e28f.bin
714249def742d6e925c5fc87f02c4271c2d8ab425e390cf65ea2ecdb960171bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xE28F 10436 bytes