Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f39d310880fa94…

MALICIOUS

PDF

77.6 KB Created: 2021-07-13 21:47:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 70e83b0bee966ebab5f9f43d3c4311cc SHA-1: b079f4ee987648eb6039139949f0cc51136e0576 SHA-256: 79f39d310880fa94f8163e280fdda430875e411e5d3c43d1ad31cda4b481bfed
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains heuristics indicating it is a phishing lure, utilizing an external URI redirector. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were extracted, the presence of a redirector URL points towards an attempt to lead the user to a malicious site, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7939

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/razvivatel/yapz/~3/AG-UZpNbJGc/square?utm_term=personal+statement+physician+associate PDF link annotation
    • https://static1.squarespace.com/static/60aac52a97a1d73ddacfe14c/t/60e924a8c4c1a734c5d6e4d8/1625892008413/signs_of_severe_hypertension.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e8668c42a7165951d9c687/1625843340793/raid_shadow_legends_best_rares_for_fire_knight.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60e8abcf9a0fc52ea427a98c/1625861071968/someone_you_loved_piano_chords.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_off0000d137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD137 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e949.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE949 15292 bytes
SHA-256: 82cef0fbf8058a689254c8d6fd8cdb50116e8d46b8e78e2270fb89ec694a3e4d
font_02_sfnt_off00011027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11027 10752 bytes
SHA-256: 1cf8e3b3842d0ad2499b5df6200a9cee4d7b71fbd4f9c4bf8678f2fa59b45161