Malicious PDF — malware analysis report

Static analysis result for SHA-256 9377f1bcebdd9e92…

MALICIOUS

PDF

99.8 KB Created: 2021-08-02 18:54:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4d894e51d5bae84cfc0a40145960fe60 SHA-1: 81409e1d09db33cba4294b4ffd2ee69911a975c3 SHA-256: 9377f1bcebdd9e92499b949696cc3df01d8ba983ddf2ba5ef4d1e5abd6e91dfe
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as 'Pdf.Phishing.Trojan' and flagged by an ML classifier, indicating malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and other domains, likely for phishing or malware delivery. The presence of numerous external URIs and the compromised CMS upload link farm heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://inwebjor.ru/uplcv?utm_term=what+hacks+can+you+use+on+2b2t PDF link annotation
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609b1a4f1d164---47163828488.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/00ee71df466d17b4769e5d8cbdc40d0f/tuwivobowowesagusej.pdfIn PDF document text
    • http://www.haztartasigepszakuzlet.hu/pics/file/pamirub.pdfIn PDF document text
    • http://setadijital.com/img/userfiles/files/pepanigodikenav.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/77573208049.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/83102462126.pdfIn PDF document text
    • http://goteneplast.se/files/images/file/fenur.pdfIn PDF document text
    • http://pkynfe.net/userfiles/file/kemiwigalepijikal.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/dufagozigonasatomosufu.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/uso089ks7sdsi8brciuv9k6704/sufuvofer.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/gatip.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/aeddb52e096d664799a2d0cf17456508/90955802367.pdfIn PDF document text
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607059dd8744c---86787384738.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/2q65un67n8n3rt5j353d97cuc4/95382261147.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/njqs8idvui29d6el82sdb2e0cu/87693520867.pdfIn PDF document text
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/e5de32a241120803f4864e036628d4a3/puzasenetimanov.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf4d11d201---pumipoduni.pdfIn PDF document text
    • https://kristinanamaste.eu/files/mawafumexufodoro.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b35e4b5faab---77523036171.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe2d7436c5---wodemufuregododu.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5b46f45014---sujataxe.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/vupolobafase.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608aec6d20812---bugupasufi.pdfIn PDF document text
    • https://svingenieria.cl/userfiles/file/legokujom.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012196.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12196 10648 bytes
SHA-256: 78e7f710a416aca70715732719bdef1816e6d2a6c0c6051f26ff7cbff8f6deea
font_01_sfnt_off00013a1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A1C 17576 bytes
SHA-256: 29a568dd190fc9b1abfe4c3346ceda18de573ebaeac8b708daae01f944e7271f
font_02_sfnt_off00016863.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16863 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1