Malicious PDF — malware analysis report

Static analysis result for SHA-256 917391bf31619f88…

MALICIOUS

PDF

89.9 KB Created: 2021-07-09 07:52:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba91f2b0fecb59e5cfed765bc8d897c3 SHA-1: 523814cd519ada1444812777280b237e9b1ed9cb SHA-256: 917391bf31619f88b0d7d4601698cd22ec4d7470a11a6ca53ade8b6211a8223b
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and ClamAV as malicious, specifically as a phishing or trojan delivery mechanism. It contains numerous embedded URLs pointing to compromised websites and link farms, suggesting an attempt to redirect users to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://laborke.ru/uplcv?utm_term=pellagra+is+a+deficiency+of+which+vitamin
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/8becf5b59495284e80fa237307166c82/kamekaxaketotenokiz.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/fc92fa35dde44052c333fe53a0f13278/16796183330.pdf
    • https://tdfstore.it/file/69262038105.pdf
    • https://laptopserwis.com/app/webroot/media/files/883431543.pdf
    • http://brukbet.com/user_images/file/tepadijipib.pdf
    • http://www.buildingmalawi.com/images/uploaded/documents/87450858478.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/7c438b3dd38df9831cd66e9196320d6e/50601665697.pdf
    • http://czdashan.cn/uploadfile/file/2021042922493473499.pdf
    • https://taevlingar.se/images/pages/file/17506279177.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b3e6dabc5---mavojiderenoku.pdf
    • http://jucal.es/images/file/27925549271.pdf
    • http://cheapmarkt.com/userfiles/file/57270167339.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/055a6950082c50361f999f7199359ae9/8334949921.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/pclc39ln23tcgrm3g6lssrmsb1/xelidefatupatadaxeli.pdf
    • http://bassbasement.org/userfiles/file/80655228751.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb656ef5c6---savatu.pdf
    • http://architettoangeli.it/userfiles/files/14933273450.pdf
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607175ae4c2c3---78408132453.pdf
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/g8djl5i37p23d7rk5gl7m87041/gitilefadoxejip.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/085a3a60c88939af2a38ca930e32877b/77885541311.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609070424fbe4---xirulek.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607a31f7e6f9d---92805600232.pdf
    • http://chiangmai-clean.com/user_img/files/14486740037.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b49622eb63d---26433065041.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_off0000fba1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBA1 16792 bytes
font_01_sfnt_off000113b3.bin
11f03c0cec5a73acb3523bfdd423817982e8a586f7e8dc50d6ab5ab23ac9b865
pdf-font-stream PDF embedded font (sfnt) at offset 0x113B3 17452 bytes
font_02_sfnt_off00014059.bin
5290c5c55dd50e3fa44b9ec675b3dd9cbdacc7cd519c2e147ddb5c44e6a8ed79
pdf-font-stream PDF embedded font (sfnt) at offset 0x14059 11188 bytes