Malicious PDF — malware analysis report

Static analysis result for SHA-256 55cd82ab9e3bdad6…

MALICIOUS

PDF

80.6 KB Created: 2021-09-19 04:23:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ea8a551ce9b87820d2c0b389dd971494 SHA-1: b27637689293c9ac8562f8f58e173169e12cc547 SHA-256: 55cd82ab9e3bdad6eab622484595faec4b956974ed1357026af3e5b4ab10d7a6
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm containing numerous embedded URLs, a common technique for phishing or distributing further malware. The document body was unreadable, but the presence of many links suggests an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://taiwan-tiaya.com/upload/tiaya_official/files/93957387245.pdf In PDF document text
    • https://nstoplana.rs/ckfinder/userfiles/files/funanojubabejabitezu.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/kovujizixesonin.pdfIn PDF document text
    • https://noventa.cz/media/files/file/58886735537.pdfIn PDF document text
    • http://miyagi.chi-kara.net/Upload/files/jitubobomewotesiteke.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/6773396502.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/97241519176.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/ef5e55a29302f5e6f550adba11416697/4300705359.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/42044913259.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613f02cd71d7d---kazimimepemakulubajali.pdfIn PDF document text
    • http://galaxyjewel.cn/uploadfile/files/66422629317.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/96924256774.pdfIn PDF document text
    • https://phm.vn/upload/files/vofunumovojugisozu.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/45499347802.pdfIn PDF document text
    • http://coytex.net/ckfinder/userfiles/files/25418163844.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/wekitavudunafef.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/90731719695.pdfIn PDF document text
    • https://deycaterers.com/ckfinder/userfiles/files/71515609009.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/21225041008.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/paminuxatowugufun.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/33551809363.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/5269277559.pdfIn PDF document text
    • http://sfipl.in/userfiles/file/rofadaxisojonojimoxal.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=hack+app+data+freePDF 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_off0000d75a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD75A 10168 bytes
SHA-256: b339fbcc44e18ca09312a17d1ba79f7d91958a5d937c7b6b14d1abb28d690caf
font_01_sfnt_off0000ee3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3D 18020 bytes
SHA-256: 141a984b193ecfd052cc7af326be664060e0654fe477f4177fb5f369f874dadf
font_02_sfnt_off00011d38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1