Malicious PDF — malware analysis report

Static analysis result for SHA-256 61dda4cf916f40c6…

MALICIOUS

PDF

81.4 KB Created: 2021-09-15 22:17:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 53e403956ccc3ea8c3aa9e3b700ff500 SHA-1: 6ed509547c8752601e60dde153ff7480f312631a SHA-256: 61dda4cf916f40c672f0b036222e15312df86cafcf37727cdab53fd503277029
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, a common tactic for phishing or distributing malware. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and numerous URLs suggest it's designed to lure users to malicious content, likely involving a second-stage download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=skullgirls+mobile+hack+apk PDF link annotation
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b99b7cddcb---forutosufidajowoda.pdfIn PDF document text
    • http://colorfusion.us/admin/images/file/wogajigigajadadaxu.pdfIn PDF document text
    • https://sreekanakananda.com/ckfinder/userfiles/files/melefuvavirubawokawibos.pdfIn PDF document text
    • http://lovesushiscv.com/uploads/files/82670598250.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/butegoleluninifigemefadut.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/37253032849.pdfIn PDF document text
    • https://satesayap.com/contents/files/repemukokazixetuvit.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/jefuzemezipoxavutebugera.pdfIn PDF document text
    • http://www.tractortools.cz/ckfinder/userfiles/files/70217053742.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/63f86429fe1131559eed10f525a5fceb/kakomobab.pdfIn PDF document text
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/58331487566.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/rimufibitufemozipekilef.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/32703827148.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/gafufapaworopalad.pdfIn PDF document text
    • http://gramercy-grand.ru/files/file/dusejuwadefebelugonopixu.pdfIn PDF document text
    • https://pottoka.info/files/galeria/files/gapixatopividixul.pdfIn PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/kemesonobeniwekalawipo.pdfIn PDF document text
    • http://www.johnrealestate.in/ckeditor-ckfinder-integration/uploads/files/20695263542.pdfIn PDF document text
    • http://britishcytology.org.uk/ckfinder/userfiles/files/73105632566.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/94111554604.pdfIn PDF document text
    • http://studiomuraca.eu/userfiles/files/kubadav.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_off0000d7fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f00d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF00D 17436 bytes
SHA-256: cac0d8e76694bcfd018397cd08721918555e0b7dbff1ebd2648d62759b227b7c
font_02_sfnt_off00011d3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D3F 11028 bytes
SHA-256: e7944142a0bde581ae916438f113684160f5d939634593eb7f0b1033669dae3e