Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b5d7dd301c02d0c…

MALICIOUS

PDF

74.9 KB Created: 2021-02-18 12:19:40 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8c2bd5b3b10103b15f1758e076198154 SHA-1: b54794714ba068276324ceddc7c9122aa7a6043b SHA-256: 7b5d7dd301c02d0c80826c20473b7a4fa70ffef77aa5d2286140f4ce707e56d1
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm, with one prominent URL pointing to 'bologen.ru'. The ML classifier and ClamAV detection strongly indicate maliciousness, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The embedded content, though heavily obfuscated, suggests a lure related to a 'user guide' to encourage clicks on these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://bologen.ru/123?utm_term=phonak+brio+2+r+user+guide
    • https://welomutulek.weebly.com/uploads/1/3/4/8/134873792/silotavofan.pdf
    • https://xuvosaxefon.weebly.com/uploads/1/3/4/6/134605895/9020294.pdf
    • https://cdn.sqhk.co/butituguxur/c1OICKk/draw_climber_apk_mod_dinheiro_infinito.pdf
    • https://cdn.sqhk.co/towevefizub/d25tgeI/62221358444.pdf
    • https://static.s123-cdn-static.com/uploads/4371509/normal_5ff636f7ac715.pdf
    • https://cdn.sqhk.co/tekuligote/lDZjcgg/medonitukubasuvefu.pdf
    • https://mutudibekakifu.weebly.com/uploads/1/3/1/3/131398274/5146993.pdf
    • https://static.s123-cdn-static.com/uploads/4388050/normal_5ffc379a02c7f.pdf
    • https://cdn-cms.f-static.net/uploads/4474992/normal_5fda3b3415d2c.pdf
    • https://zunarorukozem.weebly.com/uploads/1/3/4/0/134016655/820b829a.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://danofawo.rf.gd/16474901507.pdf
    • http://jofosomorigifo.rf.gd/44887980320.pdf
    • https://s3.amazonaws.com/wexoteluwag/safety_data_sheet_binder_table_of_contents.pdf
    • https://s3.amazonaws.com/gapuruxumeg/determiners_worksheets_for_class_8_with_answers.pdf
    • https://s3.amazonaws.com/fasudikek/icloud_bypass_tool_free_for_mac.pdf
    • http://ruxatavebokoj.epizy.com/wawiwanozuf.pdf
    • https://s3.amazonaws.com/nojemi/zukisiwisenebinuva.pdf
    • https://s3.amazonaws.com/zewimu/lirabifikavafox.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_off0000dc68.bin
5396364f4762500192060dde827420f82631623e3532d280ed3a3a7431dbe86a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC68 5392 bytes
font_01_sfnt_off0000eeb4.bin
8d102e5d54a46810a341ff3ed2534a2400322527933fe83f4be6c21021f76cba
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB4 15120 bytes