Malicious PDF — malware analysis report

Static analysis result for SHA-256 71893a7aa14de9ee…

MALICIOUS

PDF

33.6 KB Created: 2020-08-01 17:36:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4aa8051812d92ab4d2b24a477d9fd43e SHA-1: d2d8e92e6c3dfe4bbe4354b603e55264a39152da SHA-256: 71893a7aa14de9ee446f81e59ee74be56e413b469c19e42d9c0491d150e1fa3d
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the target URL and references to other PDFs hosted on various domains, suggesting a link farm or SEO manipulation 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/pify?keyword=kenmore+glasstop+stove
    • http://files.playandlearninstruction.com/uploads/1/3/0/8/130813531/3033797.pdf
    • http://files.brewtonfirst.org/uploads/1/3/0/9/130969435/kurinivafixunav-nuwoduve-lifowas-gopuv.pdf
    • http://files.qualitypreparedmeals.ca/uploads/1/3/1/8/131871740/423839.pdf
    • http://files.mywynfield.com/uploads/1/3/1/4/131453907/ede2ea4adde5a.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/3173/2132/files/xanirowemenovubalemaz.pdf
    • https://cdn.shopify.com/s/files/1/0431/4189/0208/files/rerunajosami.pdf
    • https://cdn.shopify.com/s/files/1/0428/8453/0343/files/malayalam_mallu_katha.pdf
    • https://cdn.shopify.com/s/files/1/0437/0055/1830/files/20296948619.pdf
    • https://cdn.shopify.com/s/files/1/0428/1607/7991/files/33113218210.pdf
    • https://cdn.shopify.com/s/files/1/0432/3016/7202/files/57407558006.pdf
    • https://cdn.shopify.com/s/files/1/0428/9980/0217/files/14658038712.pdf
    • https://cdn.shopify.com/s/files/1/0430/8012/2532/files/pijadafe.pdf
    • https://cdn.shopify.com/s/files/1/0431/8996/0865/files/dakituxasasire.pdf
    • https://cdn.shopify.com/s/files/1/0438/3634/2434/files/kinekijedusirofudis.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_off0000484c.bin
c5810a59c9d09a9437b7b33cf889120698c6a47d32df06f9b194e731b41d4812
pdf-font-stream PDF embedded font (sfnt) at offset 0x484C 5168 bytes
font_01_sfnt_off000059d8.bin
6a0843680646f74de31c14df4a07ad89b46a874901a713953a0af96d0ead1c53
pdf-font-stream PDF embedded font (sfnt) at offset 0x59D8 9440 bytes