Malicious PDF — malware analysis report

Static analysis result for SHA-256 661087aeb28a5ac3…

MALICIOUS

PDF

80.7 KB Created: 2021-07-15 18:41:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4a630222653c24bcd08100a86a307df4 SHA-1: 920d94ee6a4ff654ae352107289e614c812188cd SHA-256: 661087aeb28a5ac3f0b70667ee8cf132ef00290fb6bfd7c2ab4d9f9cfa577f17
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains an embedded URI pointing to the suspicious domain 'inwebjor.ru'. While no scripts were explicitly extracted, PDFs can embed JavaScript for malicious actions, and the presence of a malicious URL suggests an attempt to redirect the user to a harmful site, likely as part of a phishing or malware delivery scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://inwebjor.ru/square?utm_term=american+stafford+puppies
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60e8d92a78606b4d18578b59/1625872682561/48855963499.pdf
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60ee637d02e0767984f5e2de/1626235774366/19270046485.pdf
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ed9722151a035e9e7b3c69/1626183458450/xufigex.pdf
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e90e0266be7e490f0ed184/1625886210930/89536953054.pdf
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60edcc584ff81d3e28120a51/1626197080727/keep_talking_and_nobody_explodes_gratis_pc.pdf
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ed92e5c50d503b9d59e4ac/1626182373589/english_tamil_movie_download.pdf
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec90eb3080d76c7a51c10b/1626116331244/rebijumetubivos.pdf
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec8376e64ce5371634ce28/1626112886233/xelijojijepik.pdf
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60ed89a55eed834fcc37f03e/1626180005505/razosirorokigakap.pdf
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e8ec583ba7d954d543984a/1625877592974/use_of_computer.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d77a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD77A 16792 bytes
font_01_sfnt_off0000ef91.bin
983f517c2caa3036ff9f28eff193245bcff9f5fa64d8499eeae87198a2ddc2b0
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF91 10816 bytes
font_02_sfnt_off00010881.bin
9976314e50ec155c6361da26ece537bcf20e4ab8ac4456df40b0f72cf0f9f1c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10881 17660 bytes