Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd8f809bed51f534…

MALICIOUS

PDF

73.2 KB Created: 2021-09-15 12:07:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1d53c3e79386b1c1e55544be9b77f9cb SHA-1: bdefe4aa654d813703036171ae18b42b0c2f03d2 SHA-256: bd8f809bed51f534a70c2baeaadf040014e77b32ed0ce08625342c70b5eb9ef0
204 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and heuristics indicate it is a browser extension/update installation lure, a common social-engineering tactic. It also hosts numerous links on potentially compromised or disposable domains, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ashioke.com/images/library/File/75455011742.pdf
    • http://scuolascifondocortinadolomiti.it/userfiles/files/96144821272.pdf
    • https://angelsforwarriors.org/userfiles/files/33093277555.pdf
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16137568c37c72---84248712712.pdf
    • http://onmamtour.com/FileData/ckfinder/files/20210914_B0AD1AE6DE291079.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db272e181e---40483506362.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338790c2398---15362590170.pdf
    • https://daulte.com/ckfinder/userfiles/files/34175148331.pdf
    • http://maslag.eu/userfiles/file/49743126527.pdf
    • http://sahcarpets.com/userfiles/file/wevuxokasewedopojegi.pdf
    • http://sakurahoaanhdao.com/webroot/img/files/jitulupoju.pdf
    • http://net-work.cz/data/file/sotodawexogu.pdf
    • http://soojuspilt.ee/files/file/29301509925.pdf
    • http://vodnik48.ru/content/file/74921172555.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16135e6ca02e0e---90398617292.pdf
    • http://ydchem.cn/filespath/files/20210908055417.pdf
    • http://eco-building.cz/UserFiles/File/nebike.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/1fabb4eb12dd9af2dcee4fe79fe3fdc6/22649419784.pdf
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/19945217887.pdf
    • http://studiomanzella.com/userfiles/files/24797944351.pdf
    • http://asia-test.informacittadino.net/media/files/lumebarizatetopetenujimek.pdf
    • https://yaofangpeixun.com/upload/files/77800546287.pdf
    • http://pazzo.jp/js/upload/files/bonipufiliradopusanoxu.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/6062c1f658880c36b71ce3bad42c9892/kotalijelepadejate.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=how+to+get+pubg+uc+for+free
    • 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_off0000b9df.bin
6f4be9f191318aed7b12b8889a029bc24c7b5b7d86d5ea14dc58df7c998523b8
pdf-font-stream PDF embedded font (sfnt) at offset 0xB9DF 17868 bytes
font_01_sfnt_off0000e793.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE793 16792 bytes
font_02_sfnt_off0000ffaa.bin
4e701412cf5d6f84284bf14749f23c2a4968e9d20d8594e424a7afa6301ae299
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAA 10400 bytes