Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3e5358f570df39d…

MALICIOUS

PDF

96.2 KB Created: 2021-08-07 16:53:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1a8322fbf7059b4474099d5057041a32 SHA-1: 6c3b6fc9145e97c995c77cb241b11e9438f574f2 SHA-256: c3e5358f570df39db1d13a9b0b1ffd977f208faabb909a9232ef5b180be91af0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users into downloading further payloads or submitting sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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=english+file+intermediate+third+edition+teacher%27s+book+pdf+chomikuj
    • http://campingwithconvenience.com/files/files/gezef.pdf
    • https://adasms.fr/userfiles/file/77826085520.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bfdc0db3334---ragonaneledewa.pdf
    • https://energooptima.hu/upload/File/57714451412.pdf
    • https://www.acta-mobilier.fr/ckfinder/userfiles/files/bewonametijuvizilab.pdf
    • http://debden.org/userfiles/file/nikufonudogusonafuxaso.pdf
    • http://gustosandvic.com/ckfinder/userfiles/files/wumilufapenawifude.pdf
    • https://doctorchina168.com/upload/files/72895556331.pdf
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/9c24nj6hrv983tmnghlfmi8jb6/pedepudunod.pdf
    • http://studioaeditecne.it/userfiles/file/75534535071.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/91d657a93c31380dd88af6ad45025413/44596081324.pdf
    • https://autoteam.in/ckfinder/userfiles/files/fejajipuzureta.pdf
    • http://sbnjl.com/userfiles/files/makupevuzofinikofov.pdf
    • https://magyar-logyogyasz.hu/fileok/file/40594751962.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160b802c16d007---48609058678.pdf
    • http://jfhcoaching.nl/userfiles/files/20365157857.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8c6838e5b3---1884291697.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ecaa9422074---8522213351.pdf
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/688fbc8bf46bfea9c2e80e729e37af85/55218628154.pdf
    • http://curry-box-deluxe.de/userfiles/file/wafavozavawu.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac73ad3b92e---pijon.pdf
    • http://puppies-4u.com/clients/e/e7/e7f09595da74c05d2059c741134300d2/File/zigedujuguralew.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/da6fb6637cfe8eee42b011d9b17b21dd/videzufamezeniruduminek.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_off00010f62.bin
6af42466b858ea0a973a18bfcaea21d61da421c80ecf3fe4c0490bad3d0c2d3e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F62 11548 bytes
font_01_sfnt_off00012a1b.bin
18a453d5212d3af099ce3859df4460dfb2d1b23a61b728c6edf2e2b80c983f1b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1B 18544 bytes
font_02_sfnt_off00015942.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15942 16792 bytes