Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec4b66b456d2299b…

MALICIOUS

PDF

84.4 KB Created: 2021-06-27 22:42:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 29c9c59d9ac5d975b7a1f0d0c881c807 SHA-1: cc0bd22e783c546eab4a6c6cb03ab24fbbb80320 SHA-256: ec4b66b456d2299bea6185f58a4eb43643ebcffa184f735191d597cda794d3f0
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these compromised sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://roocenter.ru/upload/file/90280366312.pdf
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/a5e5d8207c5f0e06b303601a3115a57c/23959452330.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/6ecd3b4993c5d9c6526834935732f4cb/92041656345.pdf
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/7ebae2qat9j5p3rqgdbebguum1/kezidaterilakowewi.pdf
    • https://bandotrading.com/uploads/file/kalogebosusego.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b794835bd9---18685362669.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab27dd0c94a---88392144019.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/0105c91e0d76f650e402b28c59210ec7/kokamumo.pdf
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/8f4ba0c6134eca42395c288d3148c81f/98780023229.pdf
    • http://angarakshaksecurity.com/userfiles/file/81753220252.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/nequvviqj5ok3ei0d36kihr3a1/22930462672.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077e1ef96201---ziwanetuxipijuregun.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b052cbae171---33000410970.pdf
    • https://abugfreemind.com/userfiles/file/wipurutakebadorabomupe.pdf
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084f567e8bcf---rusikevevelijoxutos.pdf
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073749baf253---36562070174.pdf
    • https://kaowei.tw/image/files/20210623_195435.pdf
    • http://lungtransplantopen.com/clients/d/de/de7cc03d42bda6b8b84c8ac9728529bb/File/24505862104.pdf
    • http://chinazzjx.com/d/files/mubetapoboxanur.pdf
    • http://truthtube.com/UserFiles/file/mowujubaf.pdf
    • http://altaprecision.com/userfiles/file/duziwa.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/fpi5ve85pgs7o2lktaa4vrcf30/59272307831.pdf
    • http://kutyasturak.hu/images/files/walevobojunenakibubazeb.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/ca80a9ea87a9647198082afb9514d999/98418299646.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=first+signs+of+heat+exhaustion
    • 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_off0000e84b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE84B 16792 bytes
font_01_sfnt_off00010062.bin
44d4014452f6aa97262bd97b9ac7890a5d496b3776cf629a8f7480c17d6eff5e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10062 10628 bytes
font_02_sfnt_off000118a8.bin
2014350b2b60dc98a4c4db19568c492edcbb609f2ceddda41bcfe4f468a4e4f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x118A8 16876 bytes