Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21a5bea10b79e30…

MALICIOUS

PDF

85.3 KB Created: 2021-07-17 02:42:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 245704dd194682a7149a695a8f7a1260 SHA-1: 461ac1724efac85d8f2dd7cdb222007135393da3 SHA-256: c21a5bea10b79e300bc5aa4d052582a3685821f362328548136b4b6aff5129d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URLs indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f523dbc5f---waxitebufatevu.pdf In PDF document text
    • https://cambodiadriverservice.com/userfiles/file/34881827760.pdfIn PDF document text
    • http://singer-island-condos.com/userfiles/files/kijij.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210611_7407F4A8B09E43AC.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/1e3e4cb4159aa45f74b65d9a1d6193b8/ridogujoriv.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a4974882ee1---zojivisijato.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/vinirikibefumudelorejiza.pdfIn PDF document text
    • http://apcmagon.com/userfiles/tineju.pdfIn PDF document text
    • https://securitegenerale.tn/userfiles/file/gowapisawoverubukokavag.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/bajelodidedijo.pdfIn PDF document text
    • http://antifftech.com/uploadfile/file///2021051720050888.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1608028e71c267---bobuvekabibogosezuxe.pdfIn PDF document text
    • https://luminex.pl/upload/file/wirewo.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1a6666b8b---54220698488.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608240c9cbe29---lukufasexego.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072bae35e2d8---wezegewuwa.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/5984108083.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160827d863812b---40652406316.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9436415a7---bokarenilofunobefe.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/91979297447.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/6810ae45fbe429574a86d526a0ce5d8e/28652023623.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/o26gkmh46gri07gq7hhim20hor/64244067474.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160988ae923d1e---zalowexonozepov.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9d2b95647---vugupowexafekapabo.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/raduxoxazebuvulutal.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/peligewig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=my+left+sidePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eecf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000106e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E1 16668 bytes
SHA-256: 488eceed543bbdff2bb84678fedd1496da9d0cc9c62e9322cdd65daaa60eaf3f
font_02_sfnt_off000131fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131FD 9968 bytes
SHA-256: 3aa7442bbb1e5c3b07ce3600f72bf2495baad5a81f8b27d74ddc6f074ea976af