Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b6c6fa645eee939…

MALICIOUS

PDF

38.5 KB Created: 2020-09-07 11:01:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 335e8d31c533242f752040e3d05fffca SHA-1: b38a5ad558ae9ff22ee0852c6d5b164c4ebcac5e SHA-256: 9b6c6fa645eee939a9226563f625821db66099926ac0056d854e1a76a3d5e20d
152 Risk Score

Malware Insights

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

The PDF contains a high number of embedded links, many of which point to a redirector service. The primary malicious URL identified is https://ttraff.me/wix?keyword=us+customary+unit+conversion+worksheets+answers, which is flagged as a malicious redirector. The document body, though heavily obfuscated, contains references to unit conversion worksheets, suggesting a lure to disguise the malicious intent. The ML classifier strongly indicated 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.me/wix?keyword=us+customary+unit+conversion+worksheets+answers
    • https://static.usrfiles.com/ugd/c63dba_01d35818c0004d3698d74495bc40dadb.pdf
    • https://static.usrfiles.com/ugd/45e30f_b59279e6e8d4421382d93a215d98c47d.pdf
    • https://static.usrfiles.com/ugd/7dfe85_e4a5a21e3083402aa3f16cf2fcc39428.pdf
    • https://static.usrfiles.com/ugd/8de238_9cb5925f66004cbb8ccbc3abb8919c9b.pdf
    • https://static.usrfiles.com/ugd/04e6f9_449b90a505fa49a89e72348b410ee422.pdf
    • https://static.usrfiles.com/ugd/f34323_61f62dbf848143acb7c843b01ea56ef7.pdf
    • https://static.usrfiles.com/ugd/a2ebd8_d3483558f9e3482aa06c51610d36d0ef.pdf
    • https://cdn.shopify.com/s/files/1/0437/8099/7269/files/magic_bullet_recipe_book.pdf
    • https://cdn.shopify.com/s/files/1/0434/5469/3529/files/gowivurupupaworujovur.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/lunizededalusabunis.pdf
    • https://cdn.shopify.com/s/files/1/0437/5619/1893/files/algebra_worksheets_with_answers.pdf
    • https://cdn.shopify.com/s/files/1/0428/3236/3676/files/jofizojitokidobajajumi.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_off0000590d.bin
0f6ee1a30bbd5eecaa79b19397b0c36a4c6e55279d567253f2e4d5bb03f090b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x590D 5316 bytes
font_01_sfnt_off00006b10.bin
5466e1b7d199eb8ca648217a065c50f2d870e0d83217a76920365fc10e0586dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B10 10172 bytes