Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecda4d9a4f31d968…

MALICIOUS

PDF

81.1 KB Created: 2021-09-17 03:49:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 614d045c75f45fd8b7e7628cf75d5c18 SHA-1: 3058543af312dafcd5e3745d43f3133f2afe46af SHA-256: ecda4d9a4f31d9680cc5075d11e41ea7fec89a9a527bf7776272becd42f883c9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces this, indicating the PDF's primary function is to host and distribute links to potentially harmful content. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://infrive.ru/uplcv?utm_term=download+sniper+apk
    • http://opgzvh.hr/upload/file/nerotaludanuzebejomaveso.pdf
    • https://vayamcs.com/content_files/files/wogesapu.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/a2e021ffc98a88bfac81fce909736cbf/wawilubu.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/5d7f2233fcf1ed3d89146838356709d7/83047474997.pdf
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/60582017484.pdf
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/wunalarotomajotojamex.pdf
    • http://chanhungcorp.com/images/uploads/files/94750740180.pdf
    • http://hit-air.pro/ckfinder/userfiles/files/juwepigagaw.pdf
    • https://equimat-cheval.fr/file/93986967049.pdf
    • https://il-gusto.com/images/file/roburizeleveru.pdf
    • http://amsuatrust.org/survey/userfiles/files/xivitikobubozobopegapaxi.pdf
    • http://ideatity.com/ckfinder/userfiles/files/73695684037.pdf
    • https://campermagazine.tv/public/file/28440647833.pdf
    • https://maggies-handmade.com/UserFiles/files/donerawewixi.pdf
    • http://jdjcnc.com/upfolder/e/files/20210905142132.pdf
    • https://oxfordjsr.com/userfiles/file/zikemewus.pdf
    • http://teamhead.net/userfiles/file/53180384601.pdf
    • https://limsurempat.com/contents/files/27534737796.pdf
    • http://www.optimizecost.com/admin/ficheros_fckedit_subidos/jeravuvawifuzisu.pdf
    • https://profix.fr/ckfinder/userfiles/files/pelekedix.pdf
    • http://www.jindatunnel.com/up_files/file/2870287110.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f41b05ecf8---lobozofolidipifixolewajun.pdf
    • https://kingbakerypans.com/userfiles/file/vebipulogebekopi.pdf
    • https://kingdom.vn/userfiles/file/tojotuj.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_off0000d871.bin
ce217c9065f123b4f3b5327a51c5e9a10d84af0c7b414af256fab32a7118e58d
pdf-font-stream PDF embedded font (sfnt) at offset 0xD871 10464 bytes
font_01_sfnt_off0000f057.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF057 16792 bytes
font_02_sfnt_off00010869.bin
68aa97d1cf016ac9527ea8655ae313db5af5104386f24ea051ec0906632877c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10869 18220 bytes