Malicious PDF — malware analysis report

Static analysis result for SHA-256 92e3f3a1c02f79b6…

MALICIOUS

PDF

43.0 KB Created: 2020-08-29 20:33:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d2a9f194c9f00b20920465869b405249 SHA-1: 5c9c8cb000638c9a54935bf0a058e82a8067395d SHA-256: 92e3f3a1c02f79b66f45a3c224885422f44efddcfc01af09745b313281113f8e
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector at 'ttraff.ru'. The document body, though heavily obfuscated, contains text related to 'rewriting equations in slope intercept form worksheet', suggesting a lure to disguise the malicious intent. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm further supports a malicious distribution or phishing campaign.

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=rewriting+equations+in+slope+intercept+form+worksheet
    • https://static.usrfiles.com/ugd/b8c837_e26fdb7c845846f9941cd61456e8736b.pdf
    • https://static.usrfiles.com/ugd/b8c837_892d3fbbb69d41a09f1340ce68271130.pdf
    • https://static.usrfiles.com/ugd/b8c837_0e71cea722cf4ea78dcae4d1e74e6b91.pdf
    • https://static.usrfiles.com/ugd/b8c837_f3b7e6ba1dcd4a3a8e9da07b81913988.pdf
    • https://static.usrfiles.com/ugd/b8c837_b7566470a67f4d2f9b2a0e6f8c7a8f65.pdf
    • https://cdn.shopify.com/s/files/1/0434/4384/7328/files/ielts_reading_practice_academic_2018.pdf
    • https://cdn.shopify.com/s/files/1/0434/5056/4773/files/rent_agreement_format_pune_in_marathi.pdf
    • https://static.usrfiles.com/ugd/a76634_1e952ce78c27431cb0b8109d37decb24.pdf
    • https://static.usrfiles.com/ugd/b8c837_23bc1e9f24024887a160d64430be2cb8.pdf
    • https://static.usrfiles.com/ugd/ec0c41_dad0a4c0fe4a421a987107a398002add.pdf
    • https://static.usrfiles.com/ugd/b8c837_4e879196731f4fcd8f61cb0a8b758c74.pdf
    • https://static.usrfiles.com/ugd/b8c837_0a694811ad564bd38b965194c57d12a1.pdf
    • https://static.usrfiles.com/ugd/b8c837_aa2b60c55aad4b728d1a8283c69586e4.pdf
    • https://static.usrfiles.com/ugd/b8c837_56cd0f4fcd2f496ba35f911023da22b4.pdf
    • https://static.usrfiles.com/ugd/b8c837_e3eed76385524d2680b120440fff8d88.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_off00006143.bin
e01610f6cd4d6c76df18d9ec7e6d45a6e58ae126dfb660455fd19ad70bd33d15
pdf-font-stream PDF embedded font (sfnt) at offset 0x6143 5716 bytes
font_01_sfnt_off000074ab.bin
1a04b2717349fca198f3dbe19142f43619606738aa2f6385c8804dea8e836c5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x74AB 13500 bytes