Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9c2b8a908e31606…

MALICIOUS

PDF

33.4 KB Created: 2020-09-01 06:04:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 229e37950548db0facf31f1011ed520e SHA-1: 3865ebf1175035578710d944539de05bdf3312a4 SHA-256: a9c2b8a908e31606ddfe7a6fa7fa2a022d6c1ae24c832790aa99b0ec39319ba1
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link to a known malicious redirector, ttraff.me, which is likely used to deliver a secondary payload or redirect to a phishing site. The document body, though heavily obfuscated, contains the same URL and appears to be a lure for a 'carnivore herbivore omnivore worksheet'. The presence of numerous links to static.usrfiles.com, while flagged as benign, suggests a link farm or SEO poisoning tactic to improve the ranking of the malicious link. The ML classifier strongly supports the malicious nature of this PDF.

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=carnivore+herbivore+omnivore+worksheet+pdf
    • https://static.usrfiles.com/ugd/cbe7f7_2122ee2bfa274e759963060cb85cce1f.pdf
    • https://static.usrfiles.com/ugd/b8c837_893dac0340ab4e1f8b41f172dcd4a74f.pdf
    • https://static.usrfiles.com/ugd/d5d855_848c35107ab447bfa3a05884d29b9903.pdf
    • https://static.usrfiles.com/ugd/b8c837_471ef8e33f964ebba8d3aa96f8b02e83.pdf
    • https://static.usrfiles.com/ugd/b8c837_fe087dee0ac440b78ff6ddd6c68974aa.pdf
    • https://static.usrfiles.com/ugd/80bfa9_e1173089481b4749929f27a03a12ed8b.pdf
    • https://static.usrfiles.com/ugd/7ea8bb_8f79bc417db747b187c10cb5003ab067.pdf
    • https://static.usrfiles.com/ugd/b50c55_11d7a1d52ed2457caade3089fc9a1637.pdf
    • https://static.usrfiles.com/ugd/b8c837_2dfd60b35f3e44b8b92fc60f917c2efa.pdf
    • https://static.usrfiles.com/ugd/f3ecbe_d944e39aee224a02bfb22a0820dc1d05.pdf
    • https://static.usrfiles.com/ugd/93971e_f7dc186cd67c4cb3a0e89f4e1af11a67.pdf
    • https://static.usrfiles.com/ugd/cc03df_16b3b12fd5584de090e583a9cbcf7557.pdf
    • https://static.usrfiles.com/ugd/a474dd_7a53099b3e3f485a897095528287b1ee.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_off00004523.bin
4a184b3167f3767bfcb894951384e677b0c5d4ad3bbc8eec9e35cd59eb7afbd0
pdf-font-stream PDF embedded font (sfnt) at offset 0x4523 5508 bytes
font_01_sfnt_off000057c2.bin
57e1c74ec1c0bc4b73608f62a0191e393e47ce528ce3ef1613a8f5bd04b5826b
pdf-font-stream PDF embedded font (sfnt) at offset 0x57C2 9752 bytes