Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c5c5a38f1e0cf76…

MALICIOUS

PDF

80.0 KB Created: 2021-09-13 13:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 576be06f6f4e1b6d481f34ef166ffede SHA-1: 4335512802f0c5b8546b747ee670c5f915527e3d SHA-256: 0c5c5a38f1e0cf760a4fc3f814eeba55f6fc792d151c7e103bc47e7d886dc4e8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • 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 https://huntic.ru/uplcv?utm_term=how+long+can+raw+chicken+be+in+refrigerator
    • https://sananselmo.com/wysiwygfiles/file/vonatifapi.pdf
    • http://surausa.com/uploads/files/majatuset.pdf
    • http://dyccpharma.com/upload/files/30660305940.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/161392453a6818---fukogowutoratumo.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613149b1df541---dinobap.pdf
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/91551689729.pdf
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/fupusosebej.pdf
    • http://otczenacts.com/media/files/70877886944.pdf
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/34557224751.pdf
    • http://marcobernini.it/userfiles/files/48532657137.pdf
    • https://funbugs.ie/userfiles/file/rimemelumoxi.pdf
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7df814a26---84346449734.pdf
    • http://suncitygroup.ir/basefile/suncitygroupir/files/74848365844.pdf
    • http://vongtaygiay.net/media/ftp/file/71022037708.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd73fd0fdb---gokakewizujaneliseke.pdf
    • http://jinwoosmc.com/userfiles/file/fomiguruzinabe.pdf
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/kinimuwuxilemenubej.pdf
    • http://pusancard.com/userData/board/file/69480918281.pdf
    • https://dbjadow.pl/attachments/file/21039932924.pdf
    • http://www.tecnologycenter.com/admin/uploaded/fck/file/tisotub.pdf
    • http://duythuc-bearing.vn/uploads/userfiles/file/tizederosawenupetegu.pdf
    • http://www.atsamuihaus.com/image/upload/File/27743608512.pdf
    • http://studioguidobarbieri.it/userfiles/files/sirabetimepapateju.pdf
    • http://odontoflash.eu/userfiles/files/dorexebidubofolad.pdf
    • https://skinrepublic.vn/webroot/img/files/wutajame.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_off0000d738.bin
2f3957c41b4b263ce9a4777352a9fc910887474a2fd2abb0a260417de90c5aff
pdf-font-stream PDF embedded font (sfnt) at offset 0xD738 10756 bytes
font_01_sfnt_off0000eff1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF1 16792 bytes
font_02_sfnt_off00010803.bin
1a3fb2252157c8efd734c1ca1c1ade647f47c362a369175fa3890b60eee10082
pdf-font-stream PDF embedded font (sfnt) at offset 0x10803 16268 bytes