Malicious PDF — malware analysis report

Static analysis result for SHA-256 18b37c2b29d7c453…

MALICIOUS

PDF

86.3 KB Created: 2021-08-10 09:15:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2a2f0df7ac952914939c2b076388de2d SHA-1: 8a2c9656af5e8b8a60d6b6a8c4afc5a8873b118a SHA-256: 18b37c2b29d7c453a5e4a46de050ddbd9a21aab2bf05a22c6d89000b6713fe4d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan PDF. It contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is used to facilitate initial access, likely via spearphishing, by directing users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://krisoc.ru/uplcv?utm_term=descargar+grand+theft+auto+vice+city+para+android+gratis+apk
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca79961d2a---puzimus.pdf
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xojobesarowapasan.pdf
    • http://sicompk.com/survey/userfiles/files/99623558536.pdf
    • http://guides2alpes.org/uploads/file/96300710017.pdf
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/fd2d9079baa54c1b0583c5ed7bd2a6a6/muburotevikosutidojukasa.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3e745ce7fd---32213272614.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/0fdfa56e27011ea1b263c25ae91b0186/24893416002.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5b0c5213d6---dobuwovelifakigunarujosa.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/mjagqu1itu00t88ue65iihbu68/wogavumojezifitujoked.pdf
    • https://alshaabcoop.com/userfiles/file/56571756347.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b839a54bf0b---gufuban.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/7q77tbk057160sh9b6v90q1ubm/8353856215.pdf
    • https://olterus.com/contents//files/36573646843.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/fb41834598524e23b2b51212b39c2bb9/7537115393.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608954d7d8b39---wewowemipijodoxixuv.pdf
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/66491222132.pdf
    • http://zhengfutz.com/v15/Upload/file/20216271143196176.pdf
    • https://a2designbg.com/userfiles/file/nonafedasovemup.pdf
    • http://php-lounge.de/userfiles/file/52527066562.pdf
    • http://zonweringbelgie.nl/ckfinder/userfiles/files/birete.pdf
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/706469008aaf84a149049a069e6137be/32269127468.pdf
    • http://giadinhlaurenso.org/upload/files/54683040650.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_off0000e79e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE79E 16792 bytes
font_01_sfnt_off0000ffb5.bin
228b9ad91ba0c24fe742063c9037e6ea79bb0a6096963e33914525ebee191a9e
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB5 11224 bytes
font_02_sfnt_off000119d7.bin
5647c122505610a833881eb20e320ebe423a02f1b6c414c2493b52697ed131fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x119D7 18216 bytes