Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83725bfb525ba04…

MALICIOUS

PDF

73.8 KB Created: 2021-07-16 06:23:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: fee71010a4cbe8fcbab29bb35c8f32c8 SHA-1: 15d2858c760d51482f583fce242fba90da49a747 SHA-256: c83725bfb525ba0495db91f34f535d1591825be78b4307cf600c93e3a766631f
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high-severity heuristic indicating it's a phishing lure using an SEO redirector. The embedded URL, 'https://wastran.ru/square?utm_term=contract+amendment+letter+template', is the primary indicator of this phishing attempt. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely involving redirection to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8028

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://wastran.ru/square?utm_term=contract+amendment+letter+template PDF link annotation
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60f0ea847c30ad68c63bd5fa/1626401412116/songs_about_having_a_baby_boy.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60ee7d89eed6cd77ab656c6b/1626242441532/embedded_meaning_in_punjabi.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ee54dcf72ce0266e116ee4/1626232028888/28793629890.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_off0000c175.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC175 10448 bytes
SHA-256: 141023d3075360720359ff64815733bfb51d56d5158685806868e265e26a8b88
font_01_sfnt_off0000d92c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD92C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f13e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF13E 16336 bytes
SHA-256: 2bccbeb41405a2a81da2b551ebc58760752ea87821f3aa84dc1a1d2a89296a0e