Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ef44f56dba8fb57…

MALICIOUS

PDF

52.5 KB Created: 2020-09-08 19:15:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ef6173dc01def9e1bd48c761fc7204e6 SHA-1: b72ab1433be7c0c051790f9104ae1cd9a5f5167c SHA-256: 7ef44f56dba8fb57da0ff8ef45173c38e5606c90c7437f73624a8d9dcb1a7150
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF file contains embedded links, with one specifically identified as a known malicious redirector. The document body, though partially corrupted, suggests a lure related to an 'excuse letter sample format'. The primary malicious IOC is the URL 'https://ttraff.club/wix?keyword=excuse+letter+sample+format', which is likely used to redirect the user to a malicious site. The ML classifier strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ttraff.club/wix?keyword=excuse+letter+sample+format
    • https://static.usrfiles.com/ugd/83b1b3_430feeedfaa3404dbd5b882740454c2b.pdf
    • https://static.usrfiles.com/ugd/ac51ce_3fc048e6afcb4340845bfd8de8ab9e5f.pdf
    • https://static.usrfiles.com/ugd/b28561_059228a6806f47fb9c325e55d7486a3a.pdf
    • https://static.usrfiles.com/ugd/b8c837_be792a8e746a4731b6229ccd4a9c08ae.pdf
    • https://static.usrfiles.com/ugd/04c368_12285dfef0b84554a65d12a0136515ce.pdf
    • https://cdn.shopify.com/s/files/1/0432/2190/9662/files/74101746330.pdf
    • https://cdn.shopify.com/s/files/1/0439/2042/5115/files/jefulivimuf.pdf
    • https://cdn.shopify.com/s/files/1/0435/1698/5508/files/geology_types_of_unconformities.pdf
    • https://cdn.shopify.com/s/files/1/0428/8308/8547/files/89365491905.pdf
    • https://cdn.shopify.com/s/files/1/0440/7492/6230/files/alcahest_snes_portugues.pdf
    • https://static.usrfiles.com/ugd/6846fe_52456463cfae4d4fa230457ee7a6d09d.pdf
    • https://static.usrfiles.com/ugd/2d797c_a25ce2d2b4884a8abe9c63ccaa72848f.pdf
    • https://static.usrfiles.com/ugd/61c57f_9861dd6596204bc297ff8b5cfa931fd1.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00008576.bin
4aba2bb845853324476be69e5ed1bf4ff35002942389efac2b843cac1129f0e9
pdf-font-stream PDF embedded font (sfnt) at offset 0x8576 2828 bytes
font_01_sfnt_off00008f71.bin
27cacfc63ce3caa77514162285823bc6c56f0d103c294661dc0e6ff872e283f8
pdf-font-stream PDF embedded font (sfnt) at offset 0x8F71 5184 bytes
font_02_sfnt_off0000a105.bin
725a4d2713ec295650fd50384beb70fc4974b361ffa65695b352f0160ab28444
pdf-font-stream PDF embedded font (sfnt) at offset 0xA105 9940 bytes