Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb7b18aff7c5f463…

MALICIOUS

PDF

44.4 KB Created: 2020-08-30 20:50:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f98ee366e090059e46af7714bc5d3b83 SHA-1: c100e3b89f1300d3adc2a029c1257fd68a6dc8a3 SHA-256: bb7b18aff7c5f463c1f3d9ef50d2f966c64a3c353ed9771919a85ccd68729245
152 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector, ttraff.ru, which is disguised as an 'Ohio life insurance exam study guide'. This URL is presented within the document body and also identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The PDF also features a link farm, with numerous external PDF links, many hosted on static.usrfiles.com, suggesting a SEO poisoning or link farm tactic. 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.ru/wix?keyword=ohio+life+insurance+exam+study+guide
    • https://static.usrfiles.com/ugd/be19e1_a15d5ac9b1a34a64a5e020e68bc843c5.pdf
    • https://static.usrfiles.com/ugd/b8c837_4a0d3bf25dd049388d06aee2dfef8673.pdf
    • https://static.usrfiles.com/ugd/b8c837_f3b86c16dfe740c0a94601885d5d65a7.pdf
    • https://static.usrfiles.com/ugd/d94ae5_d9577c05dbbf462da3e4a8fcae341871.pdf
    • https://static.usrfiles.com/ugd/739437_8e1de07ad0b840839841e7dc5d4b970e.pdf
    • https://cdn.shopify.com/s/files/1/0464/6354/9592/files/12043633157.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/62114329075.pdf
    • https://cdn.shopify.com/s/files/1/0432/4782/9156/files/23224517919.pdf
    • https://cdn.shopify.com/s/files/1/0437/0835/0615/files/60855648080.pdf
    • https://static.usrfiles.com/ugd/b8c837_ef2bd8778cf849fd9c7f220d72f0503f.pdf
    • https://static.usrfiles.com/ugd/b8c837_6ac85aa85a6c4456be04a1ff789b1937.pdf
    • https://static.usrfiles.com/ugd/a18aa6_a9f8288671534d5e9c6cd3ff57f053ca.pdf
    • https://static.usrfiles.com/ugd/fa6f14_b1edcd630f1e47c1b070d467c75cf664.pdf
    • https://static.usrfiles.com/ugd/b8c837_0bc6a4492a024c3e8a63f388d20d6214.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_off00006119.bin
18219bfbb496af3158364f93558bc881daf20fb72d23247fd4a18721e97d6408
pdf-font-stream PDF embedded font (sfnt) at offset 0x6119 5512 bytes
font_01_sfnt_off000073b2.bin
9cdddd3630feafe49b03d0c414fe12392e47973f6f3f1db608686ed24270ef43
pdf-font-stream PDF embedded font (sfnt) at offset 0x73B2 10252 bytes
font_02_sfnt_off00009693.bin
4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x9693 4324 bytes