Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd85861b01b94d50…

MALICIOUS

PDF

82.1 KB Created: 2021-09-13 17:18:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 06e9d59f6d1df6348b884ce8180a5b66 SHA-1: 3da61270e5042f59c9f0137ce802d557de89f23e SHA-256: cd85861b01b94d504277aafa00faa4d60cbb6ddde8d2d71ab1825552d80cd7a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains and appear to be part of a link farm designed to obscure the true destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the presence of multiple unknown URLs strongly suggest a phishing or malware distribution campaign. The ClamAV detection and ML classifier further confirm its malicious nature, likely as a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://oniceh.ru/uplcv?utm_term=download+provider+apk
    • http://homelife-superstars.com/image/files/7203709538.pdf
    • http://pjcwyy.com/upload/file/simisibolefanatizofadim.pdf
    • https://psfund.org/public/uploads/files/cms_files/kepizofubuxejoxelox.pdf
    • http://kstarsmall.net/userfiles/file///95536382386.pdf
    • https://sherwoodchamber.org/ckfinder/userfiles/files/85235849615.pdf
    • http://n-production.com/upload/fckeditor/file/larirexegeka.pdf
    • https://treasurehunterdetectors.solar-ovens.net/ckfinder/userfiles/files/pifagopaboxasuxawo.pdf
    • http://nhasachnguyenvancu.com/Images_upload/files/towikivojem.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/b3f99667b87aa69561c7f4fc952be8ac/wupez.pdf
    • http://thueotodn.com/uploads/image/files/sutuxotonimupajegopamujex.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3ab383025---dabidi.pdf
    • http://greece-ex.com/images/blog/file/93537387406.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613415797e542---22495465267.pdf
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/65019875550.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c1f4cd15b---58540188320.pdf
    • http://joinsocialbubble.com/cake/beta/userfiles/file/wuvugelatukebokos.pdf
    • http://laihoawedding.com/app/webroot/upload/files/13361300169.pdf
    • http://defhjdrjioo.friend-match.com/upload/files/dapamabawajakin.pdf
    • http://gemcom.org/userfiles/file/2141123415.pdf
    • http://lahma.pl/_u/userfiles/file/91062381295.pdf
    • https://2acontractor.it/images/file/juburafa.pdf
    • https://bisnismedsos.com/userfiles/file/80681732219.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-9-7/20210907231522577742.pdf
    • http://aqcorth.specialty-match.com/upload/files/lutonanamu.pdf
    • http://perfecturology.cafe24.com/upload/editor/imagefile/tebetasurenalopalunojap.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://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_off0000db95.bin
37434e8e9a117aba60293d5010f76890c8f931cf9636786598e41ef5f6645fb9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB95 18484 bytes
font_01_sfnt_off00010b8f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B8F 16792 bytes
font_02_sfnt_off000123a6.bin
1134fd60eaa36a82523e744c4deb065148adb2098f2f1da9a14f18ae1c326262
pdf-font-stream PDF embedded font (sfnt) at offset 0x123A6 10364 bytes