Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f2a1fe6e1093c78…

MALICIOUS

PDF

75.8 KB Created: 2021-07-14 00:43:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: a7a516aab69cf71d84c2287bc20bfe3e SHA-1: f4f387883c5d9740b5168e49912df33bde4a0afe SHA-256: 9f2a1fe6e1093c78c28973520d1ebc22e117732585ea64ae6eaaeae9cc5aceb4
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high-severity heuristic firing for a redirector link, identified as an image lure for free-download phishing. The embedded URL leads to a suspicious domain, 'crewmak.ru', which is likely used to host a phishing page. The ML classifier and ClamAV detection further support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7788

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
  • 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://crewmak.ru/square?utm_term=act+three+the+crucible+questions+and+answers PDF link annotation
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e8e0598915684aa5398791/1625874522037/letter_to_the_editor_format_class_12_cbse.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60e924de3b7e7c6334505d7c/1625892063114/9357773442.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60e8437ce3cefa6a2291186b/1625834364751/nulinaramo.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_off0000c702.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC702 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF19 10920 bytes
SHA-256: 11a41fe82883e9a1fba735725242e3a816a32f58e2e54a0136f8e60aa53b77f5
font_02_sfnt_off0000f82e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82E 16712 bytes
SHA-256: abd4f91fb31022c2b898f304c9eeb4cb2edd263a81950dacac8f94716955cf81