Malicious PDF — malware analysis report

Static analysis result for SHA-256 21121cabfe03eb4c…

MALICIOUS

PDF

87.0 KB Created: 2021-09-16 16:02:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: af01c2bec2a88346d42e6014a2ef34b4 SHA-1: da3621f41d9fe724b2da405338e087e5b87f4ae8 SHA-256: 21121cabfe03eb4cd4228bfef8e11690b8ea8a65fededa196206106d8eba50ad
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous external URIs and is structured as a link farm on disposable hosting, indicating a strong intent to redirect users to potentially malicious websites. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it is designed to facilitate initial access via spearphishing attachments and lead users to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://synerhu.ru/uplcv?utm_term=sniper+3d+fun+game PDF link annotation
    • https://marljivo.hr/userfiles/file/werapewexulasasuxurox.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/64743949806.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8fed54b73---358712848.pdfIn PDF document text
    • https://slide-bearing.com/d/files/wedoxadurunowifojoxute.pdfIn PDF document text
    • http://whatcanidoforyou.eu/publish/file/53326853298.pdfIn PDF document text
    • http://karmakonnect.org/DrumiBhatt/karmakonnect.org/Final/ckeditorimage/files/gugopedi.pdfIn PDF document text
    • https://araprinter.com/ckfinder/userfiles/files/75849792264.pdfIn PDF document text
    • http://ardennes.proximeo.com/ckfinder/userfiles/files/50413381964.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/zepovozebesebize.pdfIn PDF document text
    • https://rajatotogroup3.com/contents/files/jefazafalowigigofara.pdfIn PDF document text
    • http://ekstelekom.com/userfiles/file/pikejuvefijujufate.pdfIn PDF document text
    • https://portofcrotone.com/dati/upload/file/63186858906.pdfIn PDF document text
    • https://manorhair.com/uploads/files/202109102358435075.pdfIn PDF document text
    • https://partnyor.az/userfiles/file/xubajakijesigetuni.pdfIn PDF document text
    • http://xn--b1agaa2anfqdp.xn--p1ai/ckfinder/userfiles/files/92801570461.pdfIn PDF document text
    • https://gadesign52.com/uploads/files/202109051702594714.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/gusoxomi.pdfIn PDF document text
    • https://mygoaltv.com/ipp/images/uploads/files/75710178819.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/bakedobolilepudijede.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/27461791545.pdfIn PDF document text
    • http://pzhjintai.com/upload/files/vuzibisaxanuwusaxod.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/76520194637.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/duvevasilifapad.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/rabasukajig.pdfIn PDF document text
    • http://schuetzenfest-hemeringen.de/ablage/userfiles/files/80289193165.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_off0000ee13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE13 10756 bytes
SHA-256: baf4ff4e4af71f9876ce3cb92389053c3bdec57f0e42ad66c6d9723597f856f1
font_01_sfnt_off00010693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10693 18596 bytes
SHA-256: a9eb3c0a231532c2dde0dafa338c0fb0e25a37c6cdf4fd53369c5f11ef645e0e
font_02_sfnt_off00013636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13636 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1