Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b8a59a580bf3e80…

MALICIOUS

PDF

41.3 KB Created: 2020-08-31 14:16:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e75b64547104df566d578ec77836dbbd SHA-1: 6bfac20363ef3c2d717e304bd394082cca13b32c SHA-256: 1b8a59a580bf3e800074623a472e1f9cd262ea7a659b809ce9f5cd32bde85656
154 Risk Score

Malware Insights

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

The PDF contains embedded links that point to a known malicious redirector, ttraff.ru, disguised with a textbook-related keyword. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains references to the malicious URL and a large number of other PDF links, suggesting a link farm or redirection strategy. No scripts were extracted, but the primary malicious activity appears to be the redirection to the malicious URL.

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/pify?keyword=year+11+general+maths+textbook+pdf
    • https://static.usrfiles.com/ugd/b7ab08_3a4c3422e01743c0a45c25e6f302a44e.pdf
    • https://static.usrfiles.com/ugd/b8c837_d1850561e9a84fc1acdab69ed9269913.pdf
    • https://static.usrfiles.com/ugd/b8c837_2d5c77a6cbd8416198305a0d215f0e46.pdf
    • https://static.usrfiles.com/ugd/01e791_116605517ad04392aa7fa0154d629d7c.pdf
    • https://static.usrfiles.com/ugd/b8c837_98354f1194a24134a6492c032af1aa61.pdf
    • https://static.usrfiles.com/ugd/4f270c_176244fe62fd4e3a9bc10429a82bd5f8.pdf
    • https://static.usrfiles.com/ugd/f3cb45_30683c71c788497397962f04917174f6.pdf
    • https://static.usrfiles.com/ugd/b8c837_e261fc6a85604b87890c33fb52107b63.pdf
    • https://static.usrfiles.com/ugd/b8c837_bf6b8619589642b9b3f03b1f45378616.pdf
    • https://static.usrfiles.com/ugd/df73ab_53a8ff8b2323478680ffefa5cb1a2163.pdf
    • https://static.usrfiles.com/ugd/0bcf16_6befae1952254a69a56fa7aafe24ec2e.pdf
    • https://static.usrfiles.com/ugd/07e02c_39391e1f549e43ccae0335cf54429659.pdf
    • https://static.usrfiles.com/ugd/b8c837_756280f7b4e343b4939720676291bbec.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_off00006113.bin
f0ac224910c7e25b823b4d895d63e84462632b80d39a3b01060da1ea68d1f287
pdf-font-stream PDF embedded font (sfnt) at offset 0x6113 5740 bytes
font_01_sfnt_off00007481.bin
557cc50ba57ce7ffe122b4ef5aa6b6a4f73a29bde677269f83cddd0d16d543b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x7481 10684 bytes