Malicious PDF — malware analysis report

Static analysis result for SHA-256 aef0e725f8c129fa…

MALICIOUS

PDF

108.8 KB Created: 2021-07-16 00:16:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b8dcb08d3b102e3533656927dc58706a SHA-1: dfefdf2d280cd1f9af5937087976cab71e07d5f9 SHA-256: aef0e725f8c129fa28edf7e1a8c7eac5cb0b8a8dcf374bfcc791e94f86c0704d
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a heuristic firing for a redirector link, identified as a phishing lure. The external URI points to 'https://krisoc.ru/square?utm_term=sweet+valley+high+twins', which is likely used to redirect users to a malicious site. ClamAV also detected this file as 'Pdf.Phishing.Trojan'. No scripts were extracted, but the PDF structure and URL indicate a phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5278

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://krisoc.ru/square?utm_term=sweet+valley+high+twins PDF link annotation
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60f025541b42e761db8a0ad1/1626350932582/simetunoxibosuvika.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60f02a845740a719f4ae2b67/1626352260145/3964365809.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60efe93f7fedc2490c095ea8/1626335551595/26292837622.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec820f67baa26076bb9a5b/1626112527831/paul_hollywood_and_candice.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_off00014968.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14968 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001617f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1617F 10508 bytes
SHA-256: 1c139d430207f5424b728670de8ed50c34a78879a9bf0eed2657a3705ceb21bc
font_02_sfnt_off00017965.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17965 17512 bytes
SHA-256: a6e32b233ae4bc4b689f14be42a3955d196e3dce96e3e313ba29659e9e6014b3