Malicious PDF — malware analysis report

Static analysis result for SHA-256 939b2fd11a71a3b7…

MALICIOUS

PDF

90.7 KB Created: 2021-07-05 10:23:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d3cd17fa9b31d52413f4e490546510f1 SHA-1: 628dfe9c8d9d82b4827b3ca7cd6e693166aefe73 SHA-256: 939b2fd11a71a3b797afc7547984468c4250105c5fbfb636a68eff2778e41af2
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS 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 clues to its purpose beyond the heuristic findings.

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://pistant.ru/uplcv?utm_term=i+just+wanna+let+you+know+that+i+will+never+let+you+go
    • http://bertrandetgastineaudesigners.fr/userfiles/file/geburoxevinugetumilarevi.pdf
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/8546feb9a084f527fc1963c79f63e4b9/32545618630.pdf
    • http://bruisedreedfoundation.org/clients/4/4d/4d9d7eec3bf3a09fa0457ace138f6a4e/File/65786810207.pdf
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160886b30f00b2---tepapedilafagilojowudifo.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609da22a585aa---dozuderapubelibipa.pdf
    • http://aryajob.com/user_upload/file/90103893212.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/votolunogisosoxukuf.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c1e7486c4---35297522768.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/879b0904d283caa9e2f92403894117b0/68252279766.pdf
    • http://garmagostaran.com/Upload/file/judewano.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160856acd72b39---feboxoguzitexeponival.pdf
    • http://niestachow.pl/data/aktualnosci_imgs/file/75496587753.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c23663ea3ac---paselobirakak.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/df6fe491e7ac09c52f98e5adb33ac5c0/midavelojalumugew.pdf
    • https://aspirans.com/files/file/94498376295.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf7ab6c3d2---61293764876.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/pv1cl9ifipdeh3co7bekon2dks/reteludulez.pdf
    • http://hodgesmageefamilyreunion.com/clients/c/c9/c95619ca3ec29dd030dc8935b97378d4/File/5267545052.pdf
    • http://donationwebsites.com/clients/6/68/68901b9e08e997a22fc64c74502b39ca/File/39364737664.pdf
    • https://citrasas.com/ckfinder/userfiles/files/96725713045.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609fde60a6214---rexukadigosudali.pdf
    • http://mikomisushiwc.com/uploads/files/fagijutezavasevazolawuvep.pdf
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb786ae86c---88639889438.pdf
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c05bd83b764---vexuf.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a97791f0fb3---70170638260.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_off0000fcbd.bin
ed2eb8218dad4471b219b643b8cd2a8845fb753ecce8b926272cec32a58a9f71
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCBD 10928 bytes
font_01_sfnt_off0001160e.bin
f989c6949bce401e7bd0205044ff9384c2801a344f5659e958c98e0e6641a61c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1160E 19124 bytes
font_02_sfnt_off0001451d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1451D 16792 bytes