Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5cbc24c10fae245…

MALICIOUS

PDF

84.9 KB Created: 2021-09-02 07:06:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7e9f59ccd9b1a118bb3ecebe94d89708 SHA-1: bcab7061f5f16fd27e80308891e7f19a6a05ad55 SHA-256: b5cbc24c10fae2450bc9b3a25ec6227b1e3d069d313496e909006920f7aa0273
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised WordPress uploads, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristics point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://philabc.ru/uplcv?utm_term=large+snap+barrettes
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd54005285---fewusaxalarevususe.pdf
    • http://moyamoya.center/images/hand_uploaded/files/podolipakoxonavu.pdf
    • http://elencostruzioni.it/userfiles/files/71649278666.pdf
    • http://alphasigmaoverseas.com/userfiles/file/zobijasokej.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/jonumiterunowizoseti.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/4ebe5d78dbcac82155856f29b7eca635/zesugelobosijojoduxume.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/hs19ctvc6hn94v8sg9rjhvtaa0/4973467078.pdf
    • http://etnorom.hu/pictures/buzowasimemonuxesutezu.pdf
    • http://eprdel.cz/userfiles/file/86296523755.pdf
    • https://baobihungphu.com/media/ftp/file/rusesujenu.pdf
    • http://cmtl.in/uploads/userfiles/file/file/92024807638.pdf
    • http://juentai.com/userfiles/files/81313523435.pdf
    • http://kompletucetnictvi.cz/files/file/xuzabi.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609f8e1bd565d---60546170461.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/c6ccb114f8938454cc641ff38d504b41/79488126224.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/161039a681e9d2---tugaluropavufaviw.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081954c1edea---39394572888.pdf
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/358603db1702a700fb532c119f85ac79/dopubakedar.pdf
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b821098c421---22436099406.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4ddb0eff4---mujisomuxulubu.pdf
    • http://coming-c.com/userfiles/file/fibeboloxawovokodimi.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_off0000e85b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE85B 16792 bytes
font_01_sfnt_off00010072.bin
e03b6aaaef08254ff660511a2e9f03d56d9ceded73d0882a7c610a4639c7673d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10072 10268 bytes
font_02_sfnt_off00011769.bin
e90404154b7e47f3e684b0890b77f8ddbc181f51d09e7373c627d950f8010421
pdf-font-stream PDF embedded font (sfnt) at offset 0x11769 18004 bytes