Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b739bbc5f19ec7e…

MALICIOUS

PDF

148.8 KB Created: 2021-09-04 06:55:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2c4097a25cc04c4a9d28b7e118d49cc2 SHA-1: e3464de1f5dd6a20a3e56fea38ba4d7e73ff25be SHA-256: 4b739bbc5f19ec7e9cbc409c898ac7968ed145476b5ce866282f646553642c31
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious document, potentially leveraging embedded JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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 https://laborke.ru/uplcv?utm_term=net+management+study+material+pdf
    • http://gramercygrand.ru/files/file/62568998601.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607370bab30ed---53976297962.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9c1941492---79113970438.pdf
    • https://lionkingbali.com/uploads/file/gomowawanabujetaremezeso.pdf
    • https://rajakedua.com/contents/files/4927795536.pdf
    • http://ztkammer.at/uploads/file/sepewisezowinowosuge.pdf
    • https://cald-lighting.com/wp-content/plugins/super-forms/uploads/php/files/40960157aeaa6908dc70d454eae59ec8/posimutaluvujaxum.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f705f312a2a---34290626354.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d52cfc34848---gezatoxufow.pdf
    • https://brakos.it/file/66210854576.pdf
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/0feb797d2a247a7b9d42b79f8bad65b4/wefuge.pdf
    • https://insolite.lu/img/userfiles/files/39439427700.pdf
    • https://unicon-msk.ru/data/files/kokuwuwobovefej.pdf
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/8ceuqoo10no8nnmlphvj46fbl6/63498861456.pdf
    • http://unseretochter.ch/images/file/jasovamisuxugol.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/m6gr2a3rr27mhjt9ljiit3tb51/gakeda.pdf
    • http://fluellentrees.com/clients/58222/File/gelidejofas.pdf
    • https://deitratech.com/userfiles/file/nolexijate.pdf
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/0acdcfb60dd437e70397c3e886daef7d/xizixofaro.pdf
    • https://eminencesolutions.in/resources/userfiles/file/31620638696.pdf
    • http://ser-buk.com/userfiles/file/pevoxer.pdf
    • http://olgapolyakova.com/files/files/85544050148.pdf
    • https://www.lipca.com/ckfinder/userfiles/files/38476702183.pdf
    • http://emeat.ru/var/files/wakopijisuximix.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_off0001e162.bin
d4404cdf505d13ff30724836d2917ea0a887e5ed7eccff8b452ff2276859aaa2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1E162 10912 bytes
font_01_sfnt_off0001fa69.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1FA69 16792 bytes
font_02_sfnt_off0002127b.bin
b8c9558f5ebaa92bb68204151cc99a31ffeb51bab0215f57c122c5fa0054d8b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x2127B 19604 bytes