Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f99a4c48d09728f…

MALICIOUS

PDF

37.3 KB Created: 2020-08-30 19:11:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: db5cacad87e1cf8b0ce1effada1ac7d8 SHA-1: 3600c4be8547d77e82986f2003d338632902bc41 SHA-256: 3f99a4c48d09728f66632b7817d50e6da9722d4e437779566999d312affc2e57
152 Risk Score

Malware Insights

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

The PDF file contains a heuristic firing for PDF_MALICIOUS_REDIRECTOR_LINK, indicating it directs users to malicious infrastructure. Additionally, PDF_SEO_LINK_FARM suggests the document is part of a link farm, likely to improve search engine ranking for malicious content. The primary malicious IOC is the redirector URL, which is used to lure victims. No scripts were extracted, and the document body is heavily obfuscated.

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/wix?keyword=operations+research%253A+applications+and+algorithms
    • https://static.usrfiles.com/ugd/e3c460_970fa16c7e694de7b6722cb66c1509ce.pdf
    • https://static.usrfiles.com/ugd/b8c837_599af717375b49ce8ebeaa38fab98f12.pdf
    • https://static.usrfiles.com/ugd/b8c837_441e3a808b99455dab9bd83af84f3a4f.pdf
    • https://static.usrfiles.com/ugd/b8c837_94a734d428014021b55e1f01f855b377.pdf
    • https://cdn.shopify.com/s/files/1/0436/4291/2926/files/seven_songs_of_merlin.pdf
    • https://cdn.shopify.com/s/files/1/0431/9461/3924/files/advanced_life_support_2017_malaysia.pdf
    • https://cdn.shopify.com/s/files/1/0436/4229/0336/files/troy_bilt_pressure_washer_2800_psi_manual.pdf
    • https://cdn.shopify.com/s/files/1/0433/0763/0747/files/aia_singapore_change_of_address_form.pdf
    • https://cdn.shopify.com/s/files/1/0428/5969/2198/files/63718224191.pdf
    • https://cdn.shopify.com/s/files/1/0434/0586/9213/files/42911263644.pdf
    • https://cdn.shopify.com/s/files/1/0431/6325/4944/files/vasapomorejereb.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000044d6.bin
0fe66b780ae7224ce5d406a0245dc0d7c3d939e84afc6e2446addfb81f5c99d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x44D6 5352 bytes
font_01_sfnt_off000056cf.bin
d13ee5f527eee11a3c696a2d974d91a16f225b93d30b4b5287714373f726bb56
pdf-font-stream PDF embedded font (sfnt) at offset 0x56CF 10360 bytes
font_02_sfnt_off00007a37.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A37 4324 bytes