Malicious PDF — malware analysis report

Static analysis result for SHA-256 de89c623f66d3385…

MALICIOUS

PDF

77.6 KB Created: 2021-06-21 17:57:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 2ae3f68dd2ca2b44e370dd29edcad099 SHA-1: 7e337febae29e3c4593f2febb3b65abc0254115e SHA-256: de89c623f66d33851b474e800e58efc65664bae332caf1adddd374bcc970835d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm used for distributing malicious content or redirecting users to phishing pages. The presence of external URIs and link farm heuristics points towards an attempt to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://queure.ru/uplcv?utm_term=ap+calculus+bc+practice+exam+2020 PDF link annotation
    • http://ahlhy.com/uploads/file/272325463453.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/8135f1ae9471a6116397ac7912f16a2a/31710463057.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/343fa20eacdb57328ca282b723a38367/vasiwokubawupadapibonajo.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021050310180773499.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a456911b5df---fuxumutedusiwek.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/38ejg3oludve29p4ggjer99o85/joxurasovojupuzejoju.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/mifexuvafisof.pdfIn PDF document text
    • https://ltanimalpark.com/wp-content/plugins/super-forms/uploads/php/files/14580b9a2bf3a9b5ca5191a36bc60aec/12177404381.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/64e8d461d577b83c8f74a0da88680d85/nevumimubaxebaligijigupu.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/smonj4or0uthgl13bt2in5l023/87496796451.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/38782889307.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/9d1b4f007c15557c7e8a89a1953b0ecd/magepotozajifopifepewe.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076eb156d1a9---38016418035.pdfIn PDF document text
    • http://ecogestval.com/userfiles/file/7188252682.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/1a916a756910cc35e16e41b7555dcdb5/88872775707.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000f2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2EF 5548 bytes
SHA-256: 1153ef18474a4fb1e38dfaafeb4d67c65e1301699d514812a35370ffd4ff68c6
font_01_sfnt_off000105b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B6 10616 bytes
SHA-256: 92259645eb30809264153bacaa436c6e4f7826484be11899b6043e4a8099696d