Malicious PDF — malware analysis report

Static analysis result for SHA-256 8193fbcd337d4812…

MALICIOUS

PDF

97.8 KB Created: 2021-07-02 08:09:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 38d816aea8d0f8d6b2a599e96ba24b40 SHA-1: 5f858afd3ebd446e89d32c8dc683b7987f273dc2 SHA-256: 8193fbcd337d481261dbe8c65ade9650d241a96ec607488e8b6ff1014789ffce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links to external websites, many of which are hosted on compromised CMS upload directories or appear to be part of a link farm designed to obscure the true destination. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of using disposable hosting for these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 https://smidgel.ru/uplcv?utm_term=biltmore+christmas+tickets+2020
    • http://habitat3.eu/userfiles/files/tikizujujuzukazetixi.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608455890ce1b---29111648475.pdf
    • http://prestopc.it/upload/file/jodolekokunof.pdf
    • http://noithattamphuong.com/upload/files/rorexetinadefoduwipobama.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608032edc524c---13262553204.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160847c868de55---55156346758.pdf
    • http://airconbank.com/upload/fckeditor/file/xutumevinodopi.pdf
    • http://assistance.uz/images/shared/file/56094197074.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16098fca09d4fb---21114185619.pdf
    • http://brightwayconsultancyservices.com/userfiles/file/xanakado.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16087cd3a9db37---jibawi.pdf
    • https://edmaker.site/wp-content/plugins/super-forms/uploads/php/files/01776cdbc1634d57ac0fdd03b78c3f07/2957409716.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/19e3tufclkrqbctnbqf7f6bnql/zajilotiririwuso.pdf
    • https://piuspvc.it/userfiles/file/dozixokanuvunowob.pdf
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/rapaxuwosevubifipe.pdf
    • https://clubforeducation.com/FCKeditor/userfiles/file/17084438831.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/3rip106ilo0rfuhfku8ptsef03/84281758639.pdf
    • http://acecaalcoy.com/userfiles/file/64407510553.pdf
    • http://bighost.vn/uploads/userfiles/file/jisekumezawemikofaduden.pdf
    • http://ck-kutnahora.cz/gais/image/file/zipovenudilitowezadotoli.pdf
    • http://inezorviskids.com/clients/37546/File/76614638545.pdf
    • https://telenovella-bg.com/files/tawed.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_off000117df.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x117DF 16792 bytes
font_01_sfnt_off00012ff6.bin
50d0b5267ecf8dc47dd77838c23abef42f87ff964934034f6b0b2fa077f7a804
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FF6 10776 bytes
font_02_sfnt_off000148de.bin
4bf02841cc3f2651feeeb70de7fae59513172730297633e72852f8d406beaa2b
pdf-font-stream PDF embedded font (sfnt) at offset 0x148DE 18080 bytes