Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b50caddc44669dd…

MALICIOUS

PDF

87.4 KB Created: 2021-09-07 19:11:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8cdc4dd5998980de9b39434e41585a4a SHA-1: 15b02586785ee7ffe8bca273d7ed5096674670cb SHA-256: 4b50caddc44669ddfb2f3385521dc8b78e03e08f5ecb97d02f55a45e0221c2fa
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The file's structure and URL patterns are consistent with a spearphishing attachment used to lure victims to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://study-go.info/wp-content/plugins/super-forms/uploads/php/files/bb07ca635ae82789e59e8040fa04ffe7/90553482554.pdf In PDF document text
    • http://www.gdchgs.com/admin/img/files/bujipunave.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/26527569096.pdfIn PDF document text
    • https://psihodesk.ro/ckfinder/userfiles/files/zomaxidu.pdfIn PDF document text
    • https://zhbiotech.com/CKEdit/upload/files/42993904574.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/73272812452.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/67511114404.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1a0970955---65665743182.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/fukip.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/191302544222.pdfIn PDF document text
    • https://avela.md/userfiles/file/98828824585.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608162599f143---47133820711.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/66455206373.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/ef08edn4epc1rcpakh8sc6k9oi/95474084456.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/bbeeac04837a413a2ebba78844dc0f1c/14771545549.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099a322e41e4---sipujedolikepes.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/12070455349.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/xiraxuwunumokuwixu.pdfIn PDF document text
    • http://chayka-svg.ru/files/kuvizax.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606c754fd2378---49511604644.pdfIn PDF document text
    • http://webursitet.org/Files/file/karugijamemaze.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/l92e52i25ijjp8mcmv07opmifi/20826828318.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/fixotagivalefiwawe.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/87769946484.pdfIn PDF document text
    • http://ashokarefrigeration.com/userfiles/file/72514516922.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/subowi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=what+if+analysis+excel+2016+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA5B 11168 bytes
SHA-256: cf998fee19173601f396301d9799c7edbedace71b83ce1eccb0f9a88c8124359
font_01_sfnt_off0001048f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1048F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA1 19272 bytes
SHA-256: b22e119135e4d2e39309d63d385c645d32f9c8f1f3a833f349d19a0264b313da