Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f1919fcfeebe38…

MALICIOUS

PDF

40.6 KB Created: 2020-11-08 03:51:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5696670aeb98c54bbd612fa04cb0924c SHA-1: 2bf88340dea6333704282f28845df82b2eb84f16 SHA-256: a9f1919fcfeebe3838d759b907f4eac450d5ba440c50e3a111b84795ae1fbca4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, identified as a link farm, with one prominent URL pointing to 'trafffi.ru'. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of embedded URLs and the link farm structure suggests an attempt to redirect users to potentially malicious content or for SEO manipulation. The document body, though heavily obfuscated, contains the primary URL.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://trafffi.ru/123?keyword=how+to+mod+a+apk+game
    • https://cdn-cms.f-static.net/uploads/4423136/normal_5f9b04aea1510.pdf
    • https://cdn-cms.f-static.net/uploads/4386839/normal_5fa097eec0b16.pdf
    • https://cdn-cms.f-static.net/uploads/4366339/normal_5fa0ba0a3ae29.pdf
    • https://cdn-cms.f-static.net/uploads/4408355/normal_5f9cb4a488f7c.pdf
    • https://cdn-cms.f-static.net/uploads/4463002/normal_5fa734cfef677.pdf
    • https://cdn-cms.f-static.net/uploads/4410694/normal_5f9752943bbf3.pdf
    • https://cdn-cms.f-static.net/uploads/4384483/normal_5f8fae2d31779.pdf
    • https://cdn-cms.f-static.net/uploads/4371808/normal_5f9a1aa42a905.pdf
    • https://cdn-cms.f-static.net/uploads/4368740/normal_5f9efb5fc4527.pdf
    • https://cdn-cms.f-static.net/uploads/4451755/normal_5fa1a1283d809.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/xebuvuwov/pc_oscilloscope_digital_storage.pdf
    • https://vufebaz.files.wordpress.com/2020/11/carstream_android_auto.pdf
    • https://xuviwobetar.files.wordpress.com/2020/11/pakosolekezamifofu.pdf
    • https://s3.amazonaws.com/fajonubinomeder/what_tools_did_the_mayans_use_for_hunting.pdf
    • https://zileluzut.files.wordpress.com/2020/11/jepumolujulomivugesa.pdf
    • https://sipekujax.files.wordpress.com/2020/11/liduzokoxojega.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000061db.bin
323d2fd1a47681720beeeb0085e36951e3e1c969a69830efde98962f6cb65d4e
pdf-font-stream PDF embedded font (sfnt) at offset 0x61DB 5088 bytes
font_01_sfnt_off00007331.bin
7d197f6f7206b6f7511fa29a226dd2242edc9da7d71f1da7c3e548df4aa8fa0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x7331 10080 bytes