Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f9157e9a0a6ac59…

MALICIOUS

PDF

81.5 KB Created: 2021-09-23 19:07:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6c0257919d3199f5f498021960ae08b5 SHA-1: 354b0915db04845960bf8ea39bcaf04d4c27360c SHA-256: 7f9157e9a0a6ac597730fd4395fd11d6e9666055c7443653663db4d055678caf
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It contains numerous external URIs and link farm patterns, suggesting an attempt to redirect users to potentially harmful websites. The presence of compromised CMS upload links further supports the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://nomylo.ru/uplcv?utm_term=how+to+screenshot+on+samsung+galaxy+tablet
    • http://thuocamakong.net/userfiles/image/file/bobotugojedidopavuribeka.pdf
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/pomigoguti.pdf
    • http://jwconsult2005.com/file_media/file_image/file/42090224261.pdf
    • http://marchmont.ru/imgs/file/fidigavepul.pdf
    • http://jonme.net/ckupload/files/gazuzopovogit.pdf
    • http://medica-eg.com/userfiles/file/15961069483.pdf
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/3961d984e09b4ca95bf0f33d1088e929/mapejunelemafow.pdf
    • http://talcmanagement.com/uploaded_files/userfiles/files/nizavuw.pdf
    • https://gizaviation.com/uploads/files/35866632586.pdf
    • https://larrialdiak.es/files/galeria/files/jisijoluruvexebu.pdf
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/2fp0o0bonebdf6gq25gig02i4u/85427150614.pdf
    • https://sportsslife.net/upload/ckfinder/files/difapevo.pdf
    • https://lazeo.nl/userfiles/file/12529148484.pdf
    • http://dietaltop.com/userfiles/files/5542601889.pdf
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/74522509862.pdf
    • http://geomanteia.com/userfiles/files/tuvegiwilagerewow.pdf
    • http://blankheich.de/images/uploads/file/gadesoxemowarezezof.pdf
    • http://www.eau-msu.ru/ckfinder/userfiles/files/86656595288.pdf
    • https://accuratesearch.com/userfiles/file/bakewinulawiwinejo.pdf
    • https://www.hermanosvalerorecio.com/ckfinder/userfiles/files/34668077345.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326f7d3adb2---makag.pdf
    • http://dealershop.es/userfiles/file/gepatemi.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/ssedaac32t138bssbh35tkh73g/dabilukegaj.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613908c476d71---masigileb.pdf
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/15019755163.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_off0000d941.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD941 16792 bytes
font_01_sfnt_off0000f153.bin
9164c19e4d2d88162640e20c464986f0a6c047000a729c7504178d7571ae8b99
pdf-font-stream PDF embedded font (sfnt) at offset 0xF153 17468 bytes
font_02_sfnt_off00011e2e.bin
aded5c2899bb01c1b5ea69b0c3f8a9f7feddefe243a0eb7d86c5e4a7f5dfbc92
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2E 11120 bytes