Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9a4b97aa5dc1892…

MALICIOUS

PDF

31.9 KB Created: 2020-08-09 07:12:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a81d1c3ecafe5e4fa6de528b2c9d6534 SHA-1: 16db41207f518d2c33d517d4d24dc7b69bb6d39c SHA-256: b9a4b97aa5dc1892ff15acab326d6b1c7f0ff411b943335460229edf9b3cdb20
150 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'ttraff.ru'. The document body, though heavily obfuscated, contains the same URL and a plausible-sounding title, 'present perfect tense exercises pdf esl library', suggesting a lure. The PDF also contains a mass external PDF link farm, with the first URL pointing to a Shopify domain, likely for SEO manipulation to increase visibility. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • 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.
  • 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=present+perfect+tense+exercises+pdf+esl+library
    • http://pibupu.folrac.com/uploads/1/3/0/8/130873995/bf7445af18.pdf
    • http://files.itsbammtastic.com/uploads/1/3/0/9/130969600/1902236.pdf
    • http://files.calpars.com/uploads/1/3/0/7/130739758/lasatopaluwexageme.pdf
    • https://cdn.shopify.com/s/files/1/0435/9444/9055/files/air_pollution_management_book.pdf
    • https://cdn.shopify.com/s/files/1/0428/0477/3031/files/roxusoraniwurajegiwuzurog.pdf
    • https://cdn.shopify.com/s/files/1/0428/3308/4575/files/3525759614.pdf
    • https://cdn.shopify.com/s/files/1/0440/3757/0710/files/pebopobukogedevuf.pdf
    • https://cdn.shopify.com/s/files/1/0436/1152/1181/files/12500326117.pdf
    • https://cdn.shopify.com/s/files/1/0431/2891/4087/files/xetezadujobuxopapuwuso.pdf
    • https://cdn.shopify.com/s/files/1/0437/3217/2965/files/jimoxoku.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/35209966956.pdf
    • https://cdn.shopify.com/s/files/1/0429/6625/3724/files/pateteredegajoluvijo.pdf
    • https://cdn.shopify.com/s/files/1/0435/5863/3631/files/nikajiluxuwiditanega.pdf
    • https://cdn.shopify.com/s/files/1/0432/0329/7438/files/fadebavezulebezogosivel.pdf
    • https://cdn.shopify.com/s/files/1/0430/1121/1425/files/77310963860.pdf
    • https://cdn.shopify.com/s/files/1/0427/6633/6167/files/vugadozomowexefasusotol.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_off00004369.bin
dd14dcb394482695c621779f9c3a60ead580fe5f7c8e78102a75fe179e6b4192
pdf-font-stream PDF embedded font (sfnt) at offset 0x4369 5460 bytes
font_01_sfnt_off0000560d.bin
6e1f7dcb62e78b1d8d8ae382a579cda2820a79778ac658bfcae42eac140ed5b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x560D 8360 bytes