Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7f60172561bbb3b…

MALICIOUS

PDF

44.6 KB Created: 2020-09-05 06:47:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd9dd607ad7b8f549901cbeb9dddb472 SHA-1: 2ad0c7e92352467ea1c638807131251a0dd264e1 SHA-256: a7f60172561bbb3bf2164d6cce8ca4d54f86464226e549c0ec9170389017c4f4
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'https://ttraff.me/wix?keyword=convert+decimal+to+percent+to+fraction+worksheet'. Additionally, it features a PDF link farm with numerous external links, many hosted on 'static.usrfiles.com'. The document body, though heavily obfuscated, contains the same malicious URL, suggesting a lure to a phishing or malware distribution site. The ML classifier also strongly indicated 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=convert+decimal+to+percent+to+fraction+worksheet
    • https://static.usrfiles.com/ugd/6350c7_bbaaf3c5405c44d3b2211e2ff749caa1.pdf
    • https://static.usrfiles.com/ugd/e2f197_b85eb01ae06347d2969724b97a1dc4eb.pdf
    • https://static.usrfiles.com/ugd/a4e402_34fec47843c84746872d51a73249c386.pdf
    • https://static.usrfiles.com/ugd/b8c837_c207b765a0f34def87e54e84cc07233c.pdf
    • https://static.usrfiles.com/ugd/8de238_1aecb8bf91b542dba7c471ae73001780.pdf
    • https://cdn.shopify.com/s/files/1/0431/1734/6965/files/virexu.pdf
    • https://cdn.shopify.com/s/files/1/0431/0319/1193/files/dragon_ball_fighterz_cell.pdf
    • https://static.usrfiles.com/ugd/724bd4_3264ab856cb64250a936bdbf694d7ecd.pdf
    • https://static.usrfiles.com/ugd/40512e_3eba5ae32a9741fabcf9da0bf68b6c9a.pdf
    • https://static.usrfiles.com/ugd/5b9a87_727e2b2344a84f6da5900a892c2b740a.pdf
    • https://static.usrfiles.com/ugd/724fb5_d7e235a91ec842e0afd81d45a656f9f1.pdf
    • https://static.usrfiles.com/ugd/b8c837_af7994be4aa845fbb6f345b214f42294.pdf
    • https://static.usrfiles.com/ugd/0047a4_fd7f043b72fa4c41a007252296ce0a13.pdf
    • https://static.usrfiles.com/ugd/2e16aa_7d91ddcb474e4acfba4ae8e67934b13a.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_off00006f56.bin
5d9e4a308b7d8847a18bf9f172b46e36877a2b4ed66f19f50faad01638506afa
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F56 5516 bytes
font_01_sfnt_off00008200.bin
0eabc8e07e8ff4dc36375825e9802d5507c40ba7f5c5bf6298c9ac6a667a08de
pdf-font-stream PDF embedded font (sfnt) at offset 0x8200 10272 bytes