Malicious PDF — malware analysis report

Static analysis result for SHA-256 a70490d904f19843…

MALICIOUS

PDF

75.9 KB Created: 2021-07-14 01:13:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: f41cccaeba48a224b3117fc6851f2598 SHA-1: 6604359575a0d98035df781dcf8d324062056894 SHA-256: a70490d904f198438d5a33a378e4dbb18607b590c4752745cf87774361e7a74d
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing attempt. The 'PDF_SEO_UTM_REDIRECTOR_LINK' heuristic specifically points to an image lure that redirects to an SEO redirector, likely for phishing purposes. Although no explicit script was found, the PDF structure and the presence of a redirector URL suggest an attempt to lure the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7788

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://feedproxy.google.com/~r/sq/ugae/~3/r_nBws6J8g8/square?utm_term=solid+to+liquid+phase+change PDF link annotation
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e89e0196754c2235d52f3e/1625857537501/23707325327.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac52a97a1d73ddacfe14c/t/60e8e4aef492d21a0f67da27/1625875630258/a_chinese_ghost_story_ii.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e87faa2de0eb47a893f6aa/1625849770866/83058030180.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_off0000c77f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC77F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF91 16624 bytes
SHA-256: 8aab1dd7d3c84996983020ac0d51d8783a0c8a2aa5f48005e140ea5c8f34500f
font_02_sfnt_off00010af4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF4 11016 bytes
SHA-256: 15ca6b27e19b6dc5c11f6c19b28db99f75df99242e2ce772ed942b6483f29725