Malicious PDF — malware analysis report

Static analysis result for SHA-256 121b4a79e1384bfc…

MALICIOUS

PDF

80.7 KB Created: 2021-09-03 16:11:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ded37d4fef8dea0c8be088f02f4dbaf3 SHA-1: ad1424f39f7080acbcbed9312dc1c8fb2d425c96 SHA-256: 121b4a79e1384bfc7bf9371fe2bd7683e2f44caf77bec6136b2636a7957ec384
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of links, many of which point to potentially compromised WordPress sites. The ML classifier and ClamAV both flagged this file as malicious, indicating a high likelihood of malicious intent. The primary function appears to be acting as a link farm to distribute further malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/v0k396cciols5va7gh6chrf8qv/90017183415.pdf In PDF document text
    • https://soudurelauziere.com/upload/editor/file/suxagamirevowepogirasib.pdfIn PDF document text
    • https://fultoys.com/userfiles/904424223.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b94263642d---viwonupow.pdfIn PDF document text
    • http://taigesw.com/upload/files/64524864580.pdfIn PDF document text
    • https://laetitiabernard.fr/images/file/94517348557.pdfIn PDF document text
    • http://fnathservices.com/upload/file/16492178971.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/4aed352e16edf1151b18fa97e082f9ba/xomubumapegozozugev.pdfIn PDF document text
    • http://michaelwilliamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/16539587349.pdfIn PDF document text
    • http://porpora.info/imagenes/imagenes_contenidos///37133891140.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/komozanofululofa.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/08030714640.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/67d9502718624a62b7998bfa82f9a64e/80384254021.pdfIn PDF document text
    • https://himalmanpower.com/ckfinder/userfiles/files/retuguvapofegakiza.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/11747416241.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/nubumopipemovula.pdfIn PDF document text
    • https://abeess.com/userfiles/file/4505507164.pdfIn PDF document text
    • https://hmradiatoriai.lt/images/files/6632044945.pdfIn PDF document text
    • https://paroles-vives.com/ckfinder/userfiles/files/80838177171.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles//files/51608041626.pdfIn PDF document text
    • http://sakem.org/userfiles/files/87091656549.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/segakadufavazufimilobo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=language+arts+worksheets+5th+grade+freePDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d65f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD65F 17180 bytes
SHA-256: 33978c16c6c59d264c67c45aa7aa2a3b25570930d3a4042a73996a29fa0dca1d
font_01_sfnt_off000102d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011aed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AED 10864 bytes
SHA-256: c808e4a3cc4b97f66b023e064d537c06a9f46b60353362e3f2bf3a10204e8a36