Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a28967540c4b70a…

MALICIOUS

PDF

75.1 KB Created: 2021-07-16 13:58:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 6ac31f70b10e192ae25f8e5b65e5d06f SHA-1: 83d857a7952b013186112031e55d0647d4af9f96 SHA-256: 8a28967540c4b70afe588b6c0c0d4c0965202f0cf637f3f403fdcd36e40e3ed2
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a high-severity heuristic indicating it's an SEO redirector link, likely for a free-download phishing lure. The embedded URL `https://archism.ru/square?utm_term=step+by+step+how+to+draw+a+butterfly` is the primary indicator of this malicious redirection. ClamAV also detected this file as `Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0`, further confirming its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7483

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://archism.ru/square?utm_term=step+by+step+how+to+draw+a+butterfly PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e88e096841b432b5ece675/1625853449570/morizojabuvujizinuj.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60f142ce9b6f23611957c40b/1626424014438/10619160447.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac52a97a1d73ddacfe14c/t/60e8c06237c4677c3461893a/1625866339051/zawipipepajiror.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60edcaebcc8e436e466387bd/1626196716127/6353076015.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_off0000c5e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5E6 10916 bytes
SHA-256: ba74aef0bc4b94eeb2ccee4140d45648f9fd0d186d3b7b8fde2193b186796474
font_01_sfnt_off0000df2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF2D 15980 bytes
SHA-256: d3dfeff1370e293487e269ff15cd3f88caa75147ba1469cb0bf7856b16800b8b
font_02_sfnt_off00010895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10895 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1