Malicious PDF — malware analysis report

Static analysis result for SHA-256 834bb019b68db6b3…

MALICIOUS

PDF

79.3 KB Created: 2021-09-17 08:22:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cce9c775210a8cc5c85c885f2997e769 SHA-1: 1b00f626a8e560f466c1b535f752df213cb499e5 SHA-256: 834bb019b68db6b37a5dbaa7a3d718ce660e8b43a44e38262472cce146f1a795
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress sites and disposable hosting domains, suggesting an attempt to distribute malicious content or conduct phishing. The presence of external URIs and link farm heuristics indicates a likely spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://synerhu.ru/uplcv?utm_term=android+development+pc+specs PDF link annotation
    • http://ags-sib.ru/ckfinder/userfiles/files/vetawogabofazova.pdfIn PDF document text
    • http://kmjmt.com/news/upload/file/210908152008492555g4gnj6.pdfIn PDF document text
    • https://gilbertems.com/videos/file/622894745.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16130d9bde3244---basikazajafajaze.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16143f564eb8b8---bedejifekuf.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/68192676870.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/96768438762.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161350171e51c7---xitikeragovasi.pdfIn PDF document text
    • http://okna-dvere-online.cz/media/upload/upload/file/50342255554.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/bc0d5232baaec2aedb539931907e1e9c/54362043068.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/10195985266.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/91487770514.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/68203644801.pdfIn PDF document text
    • https://movie2book.com/userfiles/file/xuzovulisubatiwer.pdfIn PDF document text
    • https://www.aifimm.it/admin/inc/ckfinder/userfiles/files/bafemi.pdfIn PDF document text
    • https://pasationtravellers.com/root/FCKeditor/file/69569784737.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/jegotejokof.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/pozeruwofe.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210909_74CB4E5F76D92C0C.pdfIn PDF document text
    • 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_off0000d246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD246 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA58 17904 bytes
SHA-256: 49da937cf667e3978b3efab22af06cf104a32b801cb7184c8e521abf4772372f
font_02_sfnt_off00011835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11835 10560 bytes
SHA-256: 1f6cf298486efb2f1a4bcd6486f8c48d85de862243f52ed5d5479d52269ae1e3