Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3658f4a8d77fa17…

MALICIOUS

PDF

39.5 KB Created: 2020-09-01 07:21:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e28c63087c8fad9ab6ab2ef81dacc18e SHA-1: 31844dddd2a307b83eb4cb4d143e71b67cc5db0f SHA-256: d3658f4a8d77fa17c438d8178cbad33c64af95c051f6046d9772ec07d0bc9f49
154 Risk Score

Malware Insights

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

The PDF file contains a heuristic firing for a malicious redirector link, specifically pointing to 'https://ttraff.ru/wix?keyword=advanced+strength+of+materials+nptel+pdf'. This URL is likely used to redirect the user to a malicious site. The document also contains a large number of embedded links, many of which point to external PDF files, suggesting a link farm or SEO poisoning tactic. 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.ru/wix?keyword=advanced+strength+of+materials+nptel+pdf
    • https://static.usrfiles.com/ugd/77941b_4361c64dd36c467a82f229d14bb1a65b.pdf
    • https://static.usrfiles.com/ugd/b0b521_3b34239a03d840eab647cd4f0436b585.pdf
    • https://static.usrfiles.com/ugd/a2c2bc_80edbdb35809447f8333ddefab003ff0.pdf
    • https://static.usrfiles.com/ugd/b8c837_e62216fd0ba54df38609bd2b12e6f24f.pdf
    • https://static.usrfiles.com/ugd/9f6a24_39f18f7e2db945cf9265db4cc64ee895.pdf
    • https://static.usrfiles.com/ugd/d775a9_11674e1b1fa9414096fc539f284f5a60.pdf
    • https://cdn.shopify.com/s/files/1/0430/4715/7911/files/9967262181.pdf
    • https://cdn.shopify.com/s/files/1/0429/9236/9823/files/lirasajugokeguwifubo.pdf
    • https://cdn.shopify.com/s/files/1/0432/4160/3239/files/ateles_belzebuth.pdf
    • https://cdn.shopify.com/s/files/1/0428/4055/5676/files/animal_bikes_mod_1._7._10.pdf
    • https://cdn.shopify.com/s/files/1/0429/9853/0202/files/bowflex_xtl_manual.pdf
    • https://cdn.shopify.com/s/files/1/0435/9431/7981/files/58563144315.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_off00005b00.bin
46fe0c0983e8fc385e0b7a75086b58ee629889dd22910d684950048d53f4f9fb
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B00 5620 bytes
font_01_sfnt_off00006dfe.bin
87ee8d42d40b54aa885c84a51b549d775ed956676480e1566fa097b6102ce021
pdf-font-stream PDF embedded font (sfnt) at offset 0x6DFE 10276 bytes