Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca10214a1db9f85c…

MALICIOUS

PDF

75.8 KB Created: 2021-07-16 13:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 1b9f75274599cc6f8aae02d56e88f181 SHA-1: a642a4b21a259ad5cec8deadeb2f49ff2be4f6ef SHA-256: ca10214a1db9f85c6aaefa50afa9f37e8938866f25084a889f2eddc50af1a382
76 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a heuristic firing for a 'SEO redirector link' and an 'Image lure linking to an SEO redirector (free-download phishing)'. The embedded URL points to a feedproxy service, which is often used to obscure the final destination. The ML classifier also flagged this PDF as malicious. No scripts were extracted, but the overall pattern suggests a phishing attempt to trick users into downloading malicious software or visiting a malicious website.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8872

Heuristics 4

  • 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/~3/0YvHz_IItD0/square?utm_term=free+pdf+reader+for+android+phone PDF link annotation
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60f0f180f75f957e35b4651b/1626403200483/how_do_you_combine_multiple_documents_into_one.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec8a850cf33f708d7b2498/1626114693205/ringworm_is_a.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e9022dc14ff043cd5b9966/1625883182096/nakerirububip.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec948a4f2b1c51afa52520/1626117258559/69809254903.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e953a32210ba6bce13a1b3/1625904035526/16226760008.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_off0000c9e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E3 10260 bytes
SHA-256: d30bbd8ac6663c89dcfeca757c52ea9fa9a9e8d246830c14bdc844e6629d2c0a
font_01_sfnt_off0000e0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BE 16312 bytes
SHA-256: 4cbdf7b490bf5becf94ee3fb06112dcd90b478908b9d2eb87cb9726a8837b3a6
font_02_sfnt_off00010b22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1