Malicious PDF — malware analysis report

Static analysis result for SHA-256 893af77b2a3abc69…

MALICIOUS

PDF

92.1 KB Created: 2021-06-25 18:34:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d3c6384c78b82e317aa687b6b0a76188 SHA-1: e617128747ebad08da57962c287842af655d4ccd SHA-256: 893af77b2a3abc697c00e4fa504be6047f0bf2e4631ca26dc73f01b2784229e6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many hosted on compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a focus on external redirection, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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=happy+birthday+letter+to+friend
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/c5aea0a8daa4162b747fec057fd7dac0/85530715341.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e1f9e6e0b4---tamovenunukevi.pdf
    • https://repare-ton-smartphone.com/userfiles/file/24534390146.pdf
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gitozupovizuwetuxu.pdf
    • http://pi-consulting.ch/download/51649229256.pdf
    • http://dzbnf.com/upload/file///10501554868.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c842613c73---karotumadotunarafurenutu.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16093918f57169---36617287917.pdf
    • http://esipro.fr/userfiles/file/lonugexus.pdf
    • http://konditsionery-reutov.ru/upload_picture/file/mapibinelubasosowi.pdf
    • http://changdahk.com/upload/17693181753.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608c15d483154---41930893796.pdf
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/1607953506db1a---95885871360.pdf
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/30688db005b740d38a2211de03675aec/kamuguxoku.pdf
    • http://ideas4mypool.com/userfiles/file/74938191934.pdf
    • http://www.psoealora.es/ckfinder/userfiles/files/83822442143.pdf
    • http://foto-klub.dk/userfiles/file/kuremajobumasunoviriz.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/9549e687ad4a41180edbbe492b1df408/60521500999.pdf
    • http://aivieksteslaivas.lv/userfiles/file/feduvozonulukisogesud.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5b4ecc1cd---ratuvo.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a565cbb5f43---gijokubu.pdf
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1608048d03c7eb---48739022834.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d34cab5a68---laxowupudimojigezitanenof.pdf
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/87ps1jjjknl6uj3o60sk592ub8/41604523713.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_off00010500.bin
5b3965145fb88e184b902d0fcf99f3c80fba7dddfe5492b4b2eaca7651123e79
pdf-font-stream PDF embedded font (sfnt) at offset 0x10500 10672 bytes
font_01_sfnt_off00011d14.bin
c060089b37315f8983e5e42edae294378e505da7cef3d8312acfcb22525b63a9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D14 17240 bytes
font_02_sfnt_off00014968.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14968 16792 bytes