Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9db9c4ebd5c4e12…

MALICIOUS

PDF

89.5 KB Created: 2021-07-03 09:19:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fabdabec60f33e4021e412cadd844bf0 SHA-1: 237712990b35c4f3ef26251c62fed63571911751 SHA-256: a9db9c4ebd5c4e12df8bd5fece50ee638a94e22290735fbf06b129507e53c8dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links pointing to compromised WordPress sites, indicating a link farm designed to host malicious content or phishing lures. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these compromised sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943fead818c---18911250899.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608b1f1ed901c---lizixozebupemexek.pdf
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794e105272a---55490799177.pdf
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/v23elgbqrutm7p7c9n2dcolks0/revoj.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/5k7rkb2q9g52pnvdrltd98sg6k/nutovotifigiwogofa.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080d5eaa40d9---54301824102.pdf
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/10418db2f59bedba58d29f0f65f04d0f/26185495049.pdf
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a37cf3566d5---felebolitasifiwejezuju.pdf
    • http://automsystem.com/UploadFile/file/20210510130421958.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609931e5b227f---16498887604.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607038eba9576---sabiwebutosagi.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/43b3dd29cc49b59bebe823c4078badb5/neriporizupujofavugop.pdf
    • http://erbamedica.org/userfiles/files/19677133627.pdf
    • https://coebmsf.com/userfiles/file/lapup.pdf
    • https://arerp.kr/data/file///48032539459.pdf
    • http://geo-equipe.it/userfiles/files/nakikojobadalozola.pdf
    • http://brilliantsolarpaneling.com/userfiles/file/53613063945.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a2eb5851194---guvaromumuroxilolesor.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3cc05d1b0e---43387144243.pdf
    • https://aslimitada.com/userfiles/file/surizisorazuxuj.pdf
    • https://mobistore.co.nz/wp-content/plugins/super-forms/uploads/php/files/985a9a19286e3ffc5a9d544bbd5a64bd/wixobip.pdf
    • https://communeouchamps.fr/userfiles/file/siwobul.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=agents+and+managers+for+actors
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9b9.bin
ccbb4d0102b1f938c59a05373ad672b7c6097ff4b902b7868d8631e93d5c3775
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B9 17864 bytes
font_01_sfnt_off0001285f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1285F 16792 bytes
font_02_sfnt_off00014076.bin
a7237c2e1a27f68c0bd02de1aa1571abd7b85a4cba8b3e2e5653ca6d17b5ded5
pdf-font-stream PDF embedded font (sfnt) at offset 0x14076 10660 bytes