Malicious PDF — malware analysis report

Static analysis result for SHA-256 c41fb2836a4de1a7…

MALICIOUS

PDF

37.7 KB Created: 2020-08-30 11:46:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: de7c65e2ad3266945ee960e2e4d834be SHA-1: ad8332e1a500d3fe120dea28d6c43954c9c4f43c SHA-256: c41fb2836a4de1a7e74a8a7a7e718acc3fede17d8bd662ffd7f587c5ea4caec8
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.001 User Execution: Malicious Link T1059.001 PowerShell

The PDF contains embedded links, one of which, https://ttraff.me/wix?keyword=mecanica+dos+solos+e+suas+aplica%2525C3%2525A7%2525C3%2525B5es+vol+2+download, is flagged as a malicious redirector. The document body, though heavily obfuscated, contains this same URL, suggesting it's the primary lure. The PDF also hosts a large number of other links, many pointing to static.usrfiles.com, which is likely part of a link farm for SEO poisoning. 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.me/wix?keyword=mecanica+dos+solos+e+suas+aplica%2525C3%2525A7%2525C3%2525B5es+vol+2+download
    • https://static.usrfiles.com/ugd/b8c837_72585d0f5c2d426cb60db3f11749c746.pdf
    • https://static.usrfiles.com/ugd/8cbfce_df42d1f93ffc45a18886858c776ba761.pdf
    • https://static.usrfiles.com/ugd/b8c837_486f1f31eea14163a8fc8d6835a42799.pdf
    • https://static.usrfiles.com/ugd/b8c837_912569e4c4bb43e8b098a71aeca5d8d9.pdf
    • https://static.usrfiles.com/ugd/0779a3_18468ce5258b41bb9ad0b8cdbe3e8907.pdf
    • https://static.usrfiles.com/ugd/b8c837_f813b776b3b2450196a554948a86c5eb.pdf
    • https://static.usrfiles.com/ugd/d902bb_586e4786c0b645d7bbbbfaac3640f866.pdf
    • https://static.usrfiles.com/ugd/07e02c_babe51882c7d4dacb13f90a93d400943.pdf
    • https://static.usrfiles.com/ugd/ca300b_9a414ccf96b24c3bb51d9bc625247587.pdf
    • https://static.usrfiles.com/ugd/b8c837_d6f0b977dc9247cea333156a533e5899.pdf
    • https://static.usrfiles.com/ugd/0a0016_facef881265948839b067ca1db182d75.pdf
    • https://cdn.shopify.com/s/files/1/0433/4023/4902/files/musutitozene.pdf
    • https://cdn.shopify.com/s/files/1/0437/4416/6037/files/devi_bhagavatam_in_bengali.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000050a3.bin
3474ea78fad493674ad87787d89d55806ca245ab73f9f80b382a3c2f1c6c145b
pdf-font-stream PDF embedded font (sfnt) at offset 0x50A3 5660 bytes
font_01_sfnt_off00006381.bin
0ca676600157ce8247574c637cd4b97e0cf9e55ff5549545f214b56b9c9180ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x6381 10612 bytes