Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ad4a984d839cc76…

MALICIOUS

PDF

81.8 KB Created: 2021-07-29 16:50:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 86dab7a1b41161585e6757703199ef59 SHA-1: f2fccf49e982bba5f9139a94ab5bd739f4f6f35f SHA-256: 4ad4a984d839cc76f833a16ed2b717d5e3030e691467b995f6245378792aef0a
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating it's designed to redirect users to potentially malicious websites. ClamAV detection and ML classification confirm its malicious nature, likely for phishing or malware distribution. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://chcial.ru/uplcv?utm_term=spanish+sentence+correction+worksheets+pdf
    • http://agisma.ru/files/pages/files/89247279838.pdf
    • https://szabobuszrendeles.hu/files/files/zevepuli.pdf
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/16889059895.pdf
    • https://pasarant0g3l-turbo-h1t.com/contents//files/23663149677.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c85f89c048f---jerexiwazowagasajusizof.pdf
    • http://meble-tk.pl/userfiles/file/10614581314.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1607b154da4fc9---rimefibewuki.pdf
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/657idej7gmjqh4vr5ilo61ib7d/fepodegusilanum.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/bc1e0730d4fddba9432940d2c9972102/lakipifudavunuwakebavume.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076f28f6f6e4---15617267791.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2eb4bad0fb---jofumuwakesubuz.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/a40545a736a529805514da4eb999b7f6/fujimi.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bacf1b91880---turakivit.pdf
    • http://cokhixnktientien.com/Images_upload/files/sukebum.pdf
    • http://maekalocal.com/Maeka/UserFiles/File/79397051142.pdf
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1635271e54---92532358560.pdf
    • http://amsaneeraus.fi/userfiles/files/birez.pdf
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef767f3655---80225294402.pdf
    • https://vokalensemble-vocembalo.ch/userfiles/file/fomuwuvadesanutufaj.pdf
    • http://usaoxin.com/userfiles/2021-7/file/wunizumimolufigusak.pdf
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/njia6e62avn0l9ang5a3vlm52e/35785653257.pdf
    • http://www.findvoters.com/userfiles/file/69062884505.pdf
    • http://deltastal.ru/userfiles/file/liwalumuzizokamijopi.pdf
    • http://lamexmarket.com/uploads/files/69509275567.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608547a2aaeaa---84361897379.pdf
    • http://anhbanglaw.com/userfiles/file/87630918161.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_off0000da85.bin
69ceae98d6db4789207880354130d50b83e43f5af32c1cc79ec936051727d036
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA85 10924 bytes
font_01_sfnt_off0000f3d8.bin
bbc615e3b7fb1073a6f7cf6c0538dab6f07f397d379e989f8c037cf423d5da8f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D8 17596 bytes
font_02_sfnt_off00012123.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12123 16792 bytes