Malicious PDF — malware analysis report

Static analysis result for SHA-256 cc936f6849fb0b72…

MALICIOUS

PDF

91.0 KB Created: 2021-06-25 14:07:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9c31554ff1ce1062c4fe3d1f43857cab SHA-1: b76d35170e46ad95c7d9712fbc95c03ef6dc409a SHA-256: cc936f6849fb0b72551042e6d144c514b4fb2c8fc476485b2a7e2d9fea11a607
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits a vulnerability or contains malicious content. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The primary purpose appears to be redirecting users to potentially malicious sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://oilbasaro.com/web/images/ckfinder/files/20210616200150.pdf
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/cfmulmsbkbn31nkos3vnp1ddaf/gabipef.pdf
    • http://xn--aknmedikal-yub.com/uploads/file/midusaweputofaseg.pdf
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/pjvh978apgpf01tevrbfqc7rqi/nemexanirexixune.pdf
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/d787d55ce47cf015ad0d30e8e89399ba/pigewibajiludod.pdf
    • http://smitheaster.org/clients/861344/File/laduwi.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ea6be725d---sufiretatopebix.pdf
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/tavcm8gartot2si3h5cj2ab6fa/13939424108.pdf
    • http://eastmoorclassof1970.com/clients/4/43/4343e427eb1b0a0668350338a4d6b623/File/mimumiwedigev.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/a924c1049baf6fad6fbb897d297abcce/1903095942.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609c7729e6019---11124076587.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/802eoibc9a0f9rff27b6243b13/6246837012.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607b97f7a12b2---zetunanuvagifodova.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16080338d709ab---32031350893.pdf
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/93d227e95749b7cbeec4a2217070d5e9/xovuwikelelidijuvanumub.pdf
    • https://alihuata.com/userfiles/file/97858647795.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1609a8a8925945---76344355440.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=world+of+warcraft+enchanting+guide
    • 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_off00010134.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10134 16792 bytes
font_01_sfnt_off00011946.bin
b91f39c95b0f073d8c8b6e959acd0c12382a7a55beafa7382a134423d9fa578f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11946 16824 bytes
font_02_sfnt_off0001454f.bin
e0f35a0574f2e202d0d7e8f268d96ab1ec1eac37925aadecd2ba388204c76e68
pdf-font-stream PDF embedded font (sfnt) at offset 0x1454F 10768 bytes