Malicious PDF — malware analysis report

Static analysis result for SHA-256 9333b768f67496a7…

MALICIOUS

PDF

77.1 KB Created: 2021-09-11 21:38:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 19ff775554ca4b1c8cef73ab72780c08 SHA-1: 84bc7ed814821840bbcc62c63eae1850482cc6aa SHA-256: 9333b768f67496a70575bc8607502a528ec774e1a4ea0f96b72a7e2ee9698a3d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier. It functions as a link farm, with numerous embedded URLs pointing to external resources. Several heuristics indicate that these links are hosted on compromised CMS uploads or disposable domains, suggesting an intent to distribute malicious content or phish users. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://dongtienlamnghiep.com/upload/file/nexozisegesevu.pdf
    • http://przychodnia-felinskiego.pl/uploads/editor/file/ruxavaga.pdf
    • http://bannhuaduong.net/upload/files/87411653062.pdf
    • http://autosoftware.company/autoresponders_images/files/88504932558.pdf
    • http://ukrfirework.com/images/file/41176672134.pdf
    • http://digitalpolicycouncil.org/imagenes/file/jizuvijugizepi.pdf
    • http://studiobaliva.eu/userfiles/files/gulisojarokeduxo.pdf
    • https://www.profiemg.cz/upload/ck/files/zigulekubukesu.pdf
    • https://abhrian.com/userfiles/files/71553029797.pdf
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/maluk.pdf
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/46faa777f2f1861c6e3d24c73c410ff6/25698447779.pdf
    • http://driver-jazda.pl/upload/file/zakifezufezenakozesovij.pdf
    • http://debnine.net/UserFiles/File/wekud.pdf
    • http://onlinetradeshow.ir/uploads/files/60637513639.pdf
    • https://topclassgreenery.nl/images/file/94569920310.pdf
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/db72f91761b13334ab1bfc3de07dbbf4/42261552926.pdf
    • http://tucholainfo.pl/userfiles/file/33808569945.pdf
    • http://uitetenindex.nl/images/uploads/88390391964.pdf
    • http://zrdb-drogbud.pl/Upload/file/83563437781.pdf
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133590e8b214---2155758694.pdf
    • https://rippa.pt/files/file/7312617750.pdf
    • http://nuraski.pl/wsg/userfiles/92115232142.pdf
    • http://kunjipsc.com/uploads/files/dalebeluki.pdf
    • http://charolais-hessen.de/write/userfiles/file/bexovofe.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=https+www+google+com+android+devicemanager+hl+es
    • 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_off0000c611.bin
2c322d05f345a77c17b0e4b94f38710caebeed888b147d7c79d79478ea29ed16
pdf-font-stream PDF embedded font (sfnt) at offset 0xC611 17664 bytes
font_01_sfnt_off0000f459.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF459 16792 bytes
font_02_sfnt_off00010c70.bin
607524ac7bcb28875d80c5d31835d1a1ef93a3cee880d414b3568a0e57e10ba0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C70 11104 bytes