Malicious PDF — malware analysis report

Static analysis result for SHA-256 477c6cd1837ae1b6…

MALICIOUS

PDF

72.7 KB Created: 2021-09-29 13:17:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 923c534771c144e9c54a73f76352db95 SHA-1: eeb09bfbbcc40b57d01f31877c43d167ecae035f SHA-256: 477c6cd1837ae1b60cd6e5a71eb5ae32f62e06ce13fd9d4cbfaa179dce26c4e0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are hosted on potentially disposable domains and appear to form a link farm, a common tactic for distributing malicious content or conducting phishing. The PDF structure and embedded content suggest an attempt to redirect users to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://kayapaliinsaat.net/file/25642188812.pdf In PDF document text
    • http://jjw-led.com/userfiles/file/41397147256.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/vigovazawosufikalalix.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/xugupofaxozukizujug.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210924_77A57AD22AA312B3.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/bulafipujipopipuvediluwuf.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/68823907245.pdfIn PDF document text
    • http://archive-2014.humandoc.pl/attachments/file/goxidi.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/70284346479.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161354b8d2f912---89016831004.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631872723.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/lomil.pdfIn PDF document text
    • http://dancephoto.ru/userfiles/files/fajisigodox.pdfIn PDF document text
    • https://smshealthcareservices.com/ckfinder/userfiles/files/42952063836.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/25175947933.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/32897440295.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/53474463543.pdfIn PDF document text
    • http://runwellconsulting.eu/file/file/46261016738.pdfIn PDF document text
    • http://humanlitech.com/files/files/gulekigofifemubipabakegot.pdfIn PDF document text
    • https://implantologie-deva.ro/app/webroot/files/userfiles/files/duzegebud.pdfIn PDF document text
    • http://gotoippc.com/ckfinder/userfiles/files/mijavafe.pdfIn PDF document text
    • http://astorandblack.net/emailer/userfiles/file/gumixodixijagisuzuwodofup.pdfIn PDF document text
    • https://xlquality.com/userfiles/file/dogujezebigejuwifaxibufup.pdfIn PDF document text
    • http://lactopad.com/uploads/files/64611973813.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=switch+off+dark+mode+chromePDF 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_off0000b55a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB55A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD71 10676 bytes
SHA-256: 37deb51dd19812ca94f862ac5c6959c2887c45c5b7f34214f90628775c8a7658
font_02_sfnt_off0000e60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60B 18308 bytes
SHA-256: 09179652d7b7a05811c24c2c6136b14f4fb8b4d534a19b49fc2eaedd607e125f