Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d772a3387c80dde…

MALICIOUS

PDF

72.1 KB Created: 2021-09-27 05:24:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b9e438d2e46ab9cc8b8c92d269b5ded2 SHA-1: cba49beeabfd4c3ddb7fddfa1a2fc111d90f875a SHA-256: 1d772a3387c80dded702cd5b9a82a82ea063ab8f382bd6922b1650a895ee78e8
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The presence of embedded URLs and the nature of the link farm suggest an attempt to redirect users to phishing or malware distribution sites, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pfollowers.com/ci/userfiles/files/lizer.pdf
    • https://turdv.ru/SITE/files/editor/file/zatuxunanezajiruw.pdf
    • https://gabconstruction.com/ckfinder/userfiles/files/zuriro.pdf
    • http://metalzilembo.it/userfiles/files/lurepofepat.pdf
    • http://cachnhietcacham.vn/Images_upload/files/8019516442.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/e5cd251ef39b335e8892fd073ba08f33/pebadenuluvebodano.pdf
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149095f7f921---zinasizedupugen.pdf
    • http://creativecoms.net/userfiles/file/84833328042.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134bb57160fd---mobopezise.pdf
    • https://vienhung.com/webroot/img/files/5441321028.pdf
    • http://colantuono.it/userfiles/files/99346990666.pdf
    • http://ciatic.saintelserver.com/archivos_editor/file/lokutesivagoman.pdf
    • https://alpasol.e-giant.net/upload/files/zexupasana.pdf
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/vegusepojob.pdf
    • https://nedimgame.com/calisma2/files/uploads/meludatapojolidifalep.pdf
    • http://gorisum.net/fckeditor/upload_file/file/fuvonamedoteputek.pdf
    • http://originalavto.ru/userfiles/file/jurug.pdf
    • http://bastola.org/userfiles/file/xomevolu.pdf
    • http://irvine.songhakbbq.com/uploads/files/kukezilerosoz.pdf
    • http://szpk.hu/_user/file/63087206478.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139157471535---ralemefunefekizemivewo.pdf
    • http://4grd.com/cmsimages/file/42223385535.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1613adfaab6251---4577857522.pdf
    • http://hoanhaochemical.com/uploads/files/28650477945.pdf
    • http://tydafa.com/dafa/uploadfiles/20210917062518.pdf
    • http://mgbig.com/upload_fck/file/2021-9-19/20210919175554759864.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=list+some+social+problems
    • 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_off0000b61a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB61A 16792 bytes
font_01_sfnt_off0000ce31.bin
3eb4a5250a4d33b5cef89ccd23ea3b2568f1e84fed2aa9be7bd7de5807225386
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE31 10528 bytes
font_02_sfnt_off0000e5f9.bin
37302edb59c7185ddff07c4881e973e599f53cf12cc6ad2c7127398278c7cf8a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5F9 17596 bytes