Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e1384cf476110a…

MALICIOUS

PDF

42.9 KB Created: 2020-08-31 02:33:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1d919115d5c91353e1508c088a139457 SHA-1: f0f26f5e65eefb0152f1290653aa53e77d51f381 SHA-256: 81e1384cf476110a9285a8a8033dd09eccc2ec57a99e9b7a9ea75a29b8f69d32
152 Risk Score

Malware Insights

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

The PDF file contains a significant number of embedded external links, with a critical heuristic firing indicating a PDF link to known malicious redirector infrastructure. The document body, though heavily obfuscated, also contains the URL 'https://ttraff.cc/wix?keyword=chess+opening+guidelines', which is flagged as malicious. The presence of a large link farm suggests an attempt to manipulate search engine results or to distribute malicious content through a network of seemingly benign documents.

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=chess+opening+guidelines
    • https://cdn.shopify.com/s/files/1/0437/2440/6935/files/100_most_common_english_words.pdf
    • https://cdn.shopify.com/s/files/1/0438/8909/8907/files/zajajexajiduvogafafejurer.pdf
    • https://cdn.shopify.com/s/files/1/0433/7677/1224/files/policy_manual_template.pdf
    • https://static.usrfiles.com/ugd/9219f8_0e72bd74fdab4802aeef2d007e1b5eaa.pdf
    • https://static.usrfiles.com/ugd/dcfb95_ee1813eef97f4559a3f9e971e34bd6b6.pdf
    • https://static.usrfiles.com/ugd/93c935_6692048675b7466cacef5577bf9591a5.pdf
    • https://static.usrfiles.com/ugd/a640e9_00019a0d51db40cfa9599a9a6d19101f.pdf
    • https://static.usrfiles.com/ugd/87d215_d11fff9d943d493696111e8efcec5c88.pdf
    • https://static.usrfiles.com/ugd/b8c837_2686345c256747728c1e181d2843e5d2.pdf
    • https://static.usrfiles.com/ugd/11f207_a9d77090816246f1bb16006b75a40539.pdf
    • https://static.usrfiles.com/ugd/3bcfef_51dc0391bacc40bb93a8ef04ec0710b0.pdf
    • https://cdn.shopify.com/s/files/1/0429/4259/5239/files/free_building_brick_wall_powerpoint_template.pdf
    • https://cdn.shopify.com/s/files/1/0430/8962/5250/files/mazisodusefaleje.pdf
    • https://cdn.shopify.com/s/files/1/0428/7807/5036/files/zazovubiwubinonam.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_off0000655a.bin
40f080bc8d51b35d68e4a6b35905fa5438f0bd9f2ec36d99b85963d392560401
pdf-font-stream PDF embedded font (sfnt) at offset 0x655A 4820 bytes
font_01_sfnt_off000075bf.bin
3c92cacf115ac19b5948384f31c093deadac0d2b9c4b9e4b01b308e74bcdb8ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x75BF 13036 bytes