Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c73a9b9d0c6485…

MALICIOUS

PDF

82.7 KB Created: 2021-09-21 08:44:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2bfea3fad39b00a66acc6afbf981b674 SHA-1: 02f2b26242f7f5edd733b6d91dd9230ed304c444 SHA-256: a8c73a9b9d0c6485cebd4d778c41740ce6826ad4cf1d9a34509e1f2d2f66af12
204 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of a download button lure and instructions for a password-protected archive, common tactics for disguising malicious payloads. Numerous embedded URLs point to external resources, likely for hosting or distributing the secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=touch+and+go+1998+movie+download
    • https://lbjgold.in/ckfinder/userfiles/files/zijagukogemasulezodi.pdf
    • http://brmhn.com/userfiles/file/20210916164617_8x1pgy.pdf
    • https://celebicatering.com/upload/ckfinder/files/81755459088.pdf
    • http://hermanosgolbano.com/admin/fckeditor/editor/filemanager/connectors/phpfile/bunuzomukidafo.pdf
    • https://ctsgroups.asia/images/file/92134968292.pdf
    • http://risorsaterra.it/userfiles/files/fudegimopivemos.pdf
    • http://rocb-ap.org/file_media/file_image/file/kitusemera.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d85a150a1b---62820797868.pdf
    • http://marisqueandopremios.com/campannas/file/tawuvazenelizaluzakipo.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/ed583c857d13feb87e6f7cd745493ae2/kesen.pdf
    • http://studioguidobarbieri.it/userfiles/files/78749166897.pdf
    • http://thrifthelp.com/flash/thrifthelp.com/file/balozovokemuzowegomifi.pdf
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/5e21f04a74aca132150ed8e09510f1e5/zezitovipesajimezatukov.pdf
    • http://perles-del-beya.com/userfiles/file/67061729453.pdf
    • http://unibox.lv/files/text/puleg.pdf
    • https://spandoekland.nl/userfiles/file/jegujat.pdf
    • http://ritadas.in/userfiles/file/paxituzol.pdf
    • http://elsped.hu/files/file/78201473409.pdf
    • https://bahceneryaman.net/public/content-images/files/dizolodogava.pdf
    • http://alfavit.tv/userfiles/file/wifijexikukab.pdf
    • https://hkparkkonutlari.com/image/files/gegekotabujadipixize.pdf
    • http://eubeer.vn/uploads/files/85601350607.pdf
    • http://lawngo.net/fckfiles/zepituvadab.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b477b82f00---tetabe.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_off0000de64.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE64 16792 bytes
font_01_sfnt_off0000f676.bin
b0962242a86ab2dab7d0631fa61f2c1bfbd8091fb93cb6a8a7f078115bbd4ad7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF676 17692 bytes
font_02_sfnt_off000123b4.bin
dc40deb97669a676e0cada52f8324b5ea5df59c60e08c316919d06db54469285
pdf-font-stream PDF embedded font (sfnt) at offset 0x123B4 11096 bytes