Malicious PDF — malware analysis report

Static analysis result for SHA-256 f561894de578650d…

MALICIOUS

PDF

89.4 KB Created: 2021-07-02 22:14:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b189a88483e6ac8b938d37db7e6d68e SHA-1: 7e13dad01306a3aa5ea3161a7f5838ff7685d292 SHA-256: f561894de578650df5aecabd13abc55e615856dba4ee8916bdcdc4d39a3e837a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://crewmak.ru/uplcv?utm_term=game+dev+tycoon+best+combo
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607834d7bceee---19790168091.pdf
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5bccfdfc1a---dilaledojopegokakitikij.pdf
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083f92039b02---47954866312.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a59a2d34afa---zifopilugozojezabe.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607354044856b---35830383904.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609467626a704---8462292865.pdf
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160949b7685248---benodizasap.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160796292c100f---nogozuf.pdf
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/ba239c76da611d6f1be170ebc34a7b81/kavexevavipumifiwuzor.pdf
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/c7k4pinavlm2kksi8egu4r8b82/72450620338.pdf
    • http://abaj.cz/UserFiles/File/garasopobizopaverupipa.pdf
    • http://thuexe7cho.vn/upload/files/zewonuwomuporotevojomiri.pdf
    • http://simonide.org/userfiles/file/kijajesofebaxo.pdf
    • http://ks4073.com/file_media/file_image/file/bezupigojamuke.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5e030d31f---97542625286.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d5bfc5efd---nuvokugakelanep.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/eb6cdf678d229b043099ef0b389663c2/83212742387.pdf
    • https://cbconsulting112.ca/userfiles/files/59230774531.pdf
    • http://fygl.net/uploads/file/151510001662.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7aaeabe3eb---bujefupubukiwilodavolugeb.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/16090c1238bee6---jobewonumotuzelal.pdf
    • http://austintownfitch1980.com/clients/879833/File/83386000426.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_off0000f830.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF830 16792 bytes
font_01_sfnt_off00011047.bin
3fed599cb9449afd8a425514e47d243ebb21be605f3730ccef94fe8a94d2a13f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11047 10652 bytes
font_02_sfnt_off000128b5.bin
1b1bd13f937335554d86d1df07b02c8483d1aea5f5f7d7c14a976f3abf71b270
pdf-font-stream PDF embedded font (sfnt) at offset 0x128B5 18244 bytes