Malicious PDF — malware analysis report

Static analysis result for SHA-256 a571be0327381581…

MALICIOUS

PDF

52.3 KB Created: 2020-08-30 16:32:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 21b1930c9b4f38aad7154e46d7a3c2b9 SHA-1: 17f32cfb28c297e03e9d9f3d6df66952117072c4 SHA-256: a571be032738158135b22d0e912a41c328270e4fc1ead80b59261484dbfe18f5
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link, identified by the 'PDF_MALICIOUS_REDIRECTOR_LINK' heuristic, pointing to 'https://ttraff.ru/wix?keyword=ds-160+blank+form+download'. This link is presented to the user as a 'DS-160 blank form download', indicating a social engineering lure. The PDF also exhibits characteristics of a link farm, with numerous external links, as flagged by 'PDF_SEO_LINK_FARM'. The ML classifier 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.ru/wix?keyword=ds-160+blank+form+download
    • https://static.usrfiles.com/ugd/b8c837_48d56d99f5db44099dd19650b14b9f03.pdf
    • https://static.usrfiles.com/ugd/6d59ab_6837c0793c8544cf83e31705275e3e7a.pdf
    • https://static.usrfiles.com/ugd/b8c837_63be9aad80654b8fbedc3e38fa9dc152.pdf
    • https://static.usrfiles.com/ugd/b8c837_53d15e11b23a4e0795e6ea36f5975481.pdf
    • https://static.usrfiles.com/ugd/09273f_ddab299f0651466a923ae6bd3315850e.pdf
    • https://static.usrfiles.com/ugd/834936_11aa245ce15746e095b0608c8a1fe10c.pdf
    • https://static.usrfiles.com/ugd/b8c837_d0c90cec36e9447080397cc238479b82.pdf
    • https://static.usrfiles.com/ugd/696b8a_8cb4c1a035f347dab3783aa3f3f439a0.pdf
    • https://static.usrfiles.com/ugd/b8c837_685805a2e6f94bc3a55f425cf588e642.pdf
    • https://static.usrfiles.com/ugd/e5a943_dce9b11981b34850a9c796dd333ff7d8.pdf
    • https://static.usrfiles.com/ugd/65b209_d61de1331f6a4dcfafa5db713bc0f364.pdf
    • https://static.usrfiles.com/ugd/2f8cea_7caffc2ff2534e66b4f2b5e716259550.pdf
    • https://static.usrfiles.com/ugd/b8c837_bc521027832147eca62fe0a49f0208f8.pdf
    • https://static.usrfiles.com/ugd/97634b_18fdf2fbf345492b818305b0a20db0fc.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
stream_005_off0000a86e.bin
92e1f5df90b14b46fac8f6bf4cfaa3659123fdab478a4f5ed4abacf78d3c1a33
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xA86E 18260 bytes
font_00_sfnt_off00007215.bin
c69d050928dd3aae62c9c11644eaae221c16e47aeddbaa871fafd7563b5fc3e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x7215 5728 bytes
font_01_sfnt_off0000859a.bin
283ec8b2146336f34cf68d9d9bb29a422615e508f66b7150778a60c8452a8642
pdf-font-stream PDF embedded font (sfnt) at offset 0x859A 10120 bytes