Malicious PDF — malware analysis report

Static analysis result for SHA-256 98d9323042bdb4c4…

MALICIOUS

PDF

80.6 KB Created: 2021-07-19 09:03:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0c9c0b5f374147faaded9a9f25009f1f SHA-1: 859178b25eac5e9f9b6408fa564ddf21c7439d88 SHA-256: 98d9323042bdb4c4548fb0800ed2acb6e22803505b9f48a1683890e43dbab86d
196 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggests the document is designed to trick users into installing malicious browser extensions or updates. While no scripts were directly extracted, the PDF structure and embedded URLs point to a phishing or malware distribution scheme, likely involving a social engineering lure to execute further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc34506cc7---64257881618.pdf
    • https://phoenixturkey.com/upload/ckfinder/files/mozesape.pdf
    • https://satybharat.com/ci/userfiles/files/66640931246.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a3fde02b473---wibetiluzazujemabemulu.pdf
    • http://thietkewebbacninh.com/webroot/img/files/ruwavifenaz.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57751a961c---bejevot.pdf
    • http://akcjonariusz.com/UserFiles/file/74721708613.pdf
    • http://broadmoor80.com/clients/866172/File/bozizavodenabunukavab.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e67cdc2bc2f---38049679631.pdf
    • http://jucal.es/images/file/juvozazekomamaroraletax.pdf
    • http://gibisch.biz/files/files/44334651858.pdf
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb75ad30abd---xidefasen.pdf
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5d10f1e66---valoten.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160806166c81d7---lotokuvabakimesugena.pdf
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/n0h6b1gbso1q5au8qc0b9k4uj4/17517292070.pdf
    • http://asianaccounting.com/admin/fckeditor/userfiles/file/5936560715.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/80747525227.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ed8ba21f266---wosojexejavafenuwexojuv.pdf
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/4cutfq0ah7qvepvoq547d319aa/mejasupalizovezabojelib.pdf
    • http://ksnjl.com/userfiles/files/zupigewosexelikubevem.pdf
    • https://saatyapi.com/upload/ckfinder/files/29726261500.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=stop+beating+the+bush
    • 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_off0000d6ad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6AD 16792 bytes
font_01_sfnt_off0000eec4.bin
887b1cc8c501f7d8f386b2ca6610811b7dacd8b5b4b6ed41a5ce53949b1c0fe0
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC4 10700 bytes
font_02_sfnt_off00010705.bin
f80259b6899b464b84450ea3a3e6c0423fff3d8229b92e9748c9f5cd416c5845
pdf-font-stream PDF embedded font (sfnt) at offset 0x10705 18156 bytes