Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bbbc894b2e3f06e…

MALICIOUS

PDF

74.8 KB Created: 2021-09-07 14:38:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2d7c03bf95aaf13819c38d7fc9af00dc SHA-1: 9597b1351be364bb28639eefe1bf617b73410647 SHA-256: 9bbbc894b2e3f06eccc526304b26eb6ce6830ad81704d7993a0fafbed97d9900
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. No scripts were extracted, but the overall structure points to a malicious PDF used for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://laborke.ru/uplcv?utm_term=toxicologia+clinica+pe%C3%B1a+pdf
    • http://minipit.com/data/files/sanowo.pdf
    • http://kanalizace-ul.cz/userfiles/file/lefij.pdf
    • http://otohondamientay.com/upload/files/79584458896.pdf
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/16092eee7cd4bb---vevaponiluxuv.pdf
    • http://niestachow.pl/data/aktualnosci_imgs/file/46939486084.pdf
    • http://vina2002.com/uploads/files/jawav.pdf
    • https://ldoris.com/upfile/files/20210704055615.pdf
    • http://ubytovani-budejovice.cz/picture/vtextu/file/69454761348.pdf
    • https://netkat.in/ckfinder/userfiles/files/naxiwadiwadalelimutekim.pdf
    • http://siblom.ru/files/upload/file/13789641178.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-4-29/20210429101230562642.pdf
    • http://botosani.ro/img/uploads/file/raranujavivapomobil.pdf
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/kugabafojanifonijuxug.pdf
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/89022959894.pdf
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/68195a1ad49756867c8b970f6f24a4d6/fufoj.pdf
    • https://rubfila.in/files/file/kobimuditawamimaf.pdf
    • http://badgerhillfarm.uk/najijuduruzobudis.pdf
    • http://beijinghuojia.cn/userfiles/file/zesiduditukosefikigolakaf.pdf
    • http://whsclass1968.com/clients/f/f8/f849445bb2fb8f42e7c863050dc1ba38/File/50350130461.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/qicaveglp3vjo4ih9c15mj24g5/repavenikewevabosomu.pdf
    • https://fallsplat.se/file/mewikuwoxajakonutudax.pdf
    • http://simonide.org/userfiles/file/lorajumuzoli.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b78d9a58707---zidupisagejotajurati.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b50f0d90b4a---10616308484.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/812ef5b4167c0e44f2378e992948c4bb/28254566288.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_off0000c082.bin
9b5bf6b444036c3cdc8609823b97f036c7733409a553ad557c6ccde3c7c00b77
pdf-font-stream PDF embedded font (sfnt) at offset 0xC082 10700 bytes
font_01_sfnt_off0000d8b8.bin
0b613d327f564f3e1063fc54006b848dbf0c0d66b1fa3b224f3649be73b6a91c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B8 17004 bytes
font_02_sfnt_off000103c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x103C3 16792 bytes