Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a81fdec241a9a1a…

MALICIOUS

PDF

82.5 KB Created: 2021-09-12 18:12:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a0cdc67b0066bdf9631049640be1c653 SHA-1: a2a1ab2b322abf0b1e1a69bcb3690053e05b49a6 SHA-256: 8a81fdec241a9a1aca62edb7849c2d884e05334899bf92dae3081f6409bcd9e9
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF's primary function is to act as a lure to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://irlanc.ru/uplcv?utm_term=video+recovery+workshop+apk
    • https://bonaparte.cappencms.com/templates/files/gipunozalir.pdf
    • https://adamant54.ru/userfiles/files/33836662404.pdf
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/46643773015.pdf
    • http://medtravel.pro/images/hand_uploaded/files/1779389394.pdf
    • http://lnimeina.it/userfiles/files/58159036282.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/eb48b01a354893ff02aabcd4565868a6/60372714213.pdf
    • http://rlponder.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/14221918521.pdf
    • https://darshanam.com/ckfinder/userfiles/files/birupuzoxagedazizofigux.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4840b770c---16565135233.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ebbfee8d34---97862071798.pdf
    • http://gemaeldeundobjekte.de/uploads/files/zifafixozifotaxo.pdf
    • http://gokea.org/upload/editor/files/55508463279.pdf
    • http://tlumacz-lipno.pl/pdrzewiecki/files/xomizof.pdf
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/28686330379.pdf
    • http://shinhwajudan.com/userData/board/file/xufixubavajagupas.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/a78db01d7b6f174efac97268ca0d58b3/rabetanakiranizowez.pdf
    • https://vasantviharproperties.com/userfiles/file/65610930544.pdf
    • http://ooexperience.be/assets/Image/files/fixeboxisusexoritute.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161349b95040cf---92369088736.pdf
    • http://www.reeder.ee/files/filemanager/govevidorikikaxefuwejiwap.pdf
    • http://cameradungphat.com/uploads/files/sowonuxumexogogekefamex.pdf
    • http://ballarioarchitetti.eu/userfiles/files/tobapuf.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/dea6f132ab5d0edb3d4c432d66c3e7fb/ronozatidafufitagumizupaz.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_off0000da0e.bin
84df1d863f1f7bc8d4ef0237dad41611585c9acec62f03deaf3fad3b37a5e7a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0E 18704 bytes
font_01_sfnt_off00010b9e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9E 16792 bytes
font_02_sfnt_off000123b5.bin
134b56b5c79d6acec0c458bcbf9be466ec48cc9c11ffc262ddc87c2ec669efc4
pdf-font-stream PDF embedded font (sfnt) at offset 0x123B5 10688 bytes