Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8c37db627f52b4e…

MALICIOUS

PDF

43.6 KB Created: 2020-08-06 00:58:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 171ab290fb8af6d8cceb8da085019884 SHA-1: e173229886aea1bd62a67657900c8c80e641408b SHA-256: b8c37db627f52b4e71d6a4a4e67f7bfaa5ce8b7eb0bd16da1f8827ec9f07f4ba
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a redirector service (ttraff.cc). The primary heuristic firing indicates these links lead to known malicious infrastructure. The document body, though heavily obfuscated, contains a reference to 'beginner exercises pdf' and a URL that appears to be part of the link farm. The ML classifier strongly indicates 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.cc/pify?keyword=beginner+exercises+pdf
    • http://files.tracypowerconservation.com/uploads/1/3/0/9/130969260/jarufujo-tozag-balol-maves.pdf
    • http://files.iwfgeorgia.org/uploads/1/3/1/4/131455883/dofez.pdf
    • http://files.osteopathy-chronicpain.com/uploads/1/3/2/6/132683088/sesegexamusaxab_pisiz_bizovenibujob_todejupupuz.pdf
    • https://cdn.shopify.com/s/files/1/0430/4044/0471/files/60848632823.pdf
    • https://cdn.shopify.com/s/files/1/0439/4388/7016/files/18842246410.pdf
    • https://cdn.shopify.com/s/files/1/0431/3320/6690/files/kejironisugosi.pdf
    • https://cdn.shopify.com/s/files/1/0437/1690/3080/files/29852977044.pdf
    • https://cdn.shopify.com/s/files/1/0435/5942/0063/files/altiplano_cundiboyacense.pdf
    • https://cdn.shopify.com/s/files/1/0435/7675/4344/files/72385627085.pdf
    • https://cdn.shopify.com/s/files/1/0434/2412/0984/files/76372787385.pdf
    • https://cdn.shopify.com/s/files/1/0430/4555/2277/files/32601116296.pdf
    • https://cdn.shopify.com/s/files/1/0433/5425/9606/files/xefisufavasemazikeku.pdf
    • https://cdn.shopify.com/s/files/1/0434/7772/9430/files/9461060883.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/lebalod.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mijafovaginidobu.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/
    • https://cdn.shopify.com/s/files/1/0435/7675/4344/files/7238562708

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006d43.bin
34a4c8ec26c1878f0a91e7de4bc6d7babdc87f843ebbfa979748b9c316243b5f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D43 5200 bytes
font_01_sfnt_off00007f16.bin
ea21b80eaf58e3ece3d8bff2aa73daf624f1708529759a0ca398745fe16eab54
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F16 9992 bytes