Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f8b88c96787636…

MALICIOUS

PDF

80.7 KB Created: 2021-07-14 01:39:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 194ea8f90f180467a9b0183daf0cf869 SHA-1: 8573f667a9a13c3cad1f31f4fbc92a4bf1c0e637 SHA-256: a8f8b88c96787636b8512587537ba420a0d67203e2de6d55e24b562fbd7b423c
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains heuristics indicating it is a phishing lure, utilizing an external URI that functions as an SEO redirector. ClamAV also detected this file as Pdf.Phishing.Trojan. The embedded URL, while marked as confirmed benign by the analysis tool, is part of the phishing mechanism. The PDF structure and embedded content suggest an attempt to trick the user into visiting a malicious site, likely for credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6556

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://feedproxy.google.com/~r/sq/ugae/~3/uzX87CUNjRg/square?utm_term=meaning+of+let+the+cat+out+of+the+bag PDF link annotation
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec8e9380388a1034d7eaa8/1626115732035/tixekimevuxoladuxesitobi.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60eca8e4f4b4775d04a2d3c9/1626122468541/27500956514.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ee0a8e1f51426150c949b9/1626213006956/zufovozuxazudulakakelubin.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_off0000daa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BB 16452 bytes
SHA-256: bd17c65c02f3af6d3e693cddcdf36de8a521ddb330c40bce8108432a26678ae3
font_02_sfnt_off00011d2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D2B 10580 bytes
SHA-256: 969a48bef586dda0cc43e4cb2a686465a26b234a5d1ca164ef5b20fe9d9144e0