Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf9668a5755b64de…

MALICIOUS

PDF

43.2 KB Created: 2020-08-31 18:52:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 160d3a220e53f0973c9bbdfed6b80ea7 SHA-1: 436e013a83fd61e65817d4473e4f34ade71d44a9 SHA-256: bf9668a5755b64deb60a796d058337fe20bbb6780858b6afe7187cfaa92f5b92
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains the URL 'https://ttraff.com/pify?keyword=kindergarten+esl+worksheets+free', suggesting a lure for free educational materials to redirect users to malicious infrastructure. The ML classifier also 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.com/pify?keyword=kindergarten+esl+worksheets+free
    • https://cdn.shopify.com/s/files/1/0433/0802/3966/files/batudibirexavunaniziza.pdf
    • https://cdn.shopify.com/s/files/1/0431/6309/1112/files/90043044536.pdf
    • https://cdn.shopify.com/s/files/1/0432/7941/7504/files/bewokek.pdf
    • https://static.usrfiles.com/ugd/a4d998_235383da22d84df6af456045b3d1df77.pdf
    • https://static.usrfiles.com/ugd/ddb60a_e4f32e92a2d84464bab5947299b182ad.pdf
    • https://static.usrfiles.com/ugd/7d1dc9_c3e7bee2fa9a468d9f98b0c11a0ea428.pdf
    • https://static.usrfiles.com/ugd/1b8612_d2375602e39241d0965e80efb89562e2.pdf
    • https://static.usrfiles.com/ugd/4d400c_f1c6ebad41e743a1936bf0ceb22ab9f3.pdf
    • https://static.usrfiles.com/ugd/b8c837_c156cb0b3be843ce97a3e570bb728c2c.pdf
    • https://static.usrfiles.com/ugd/784815_c30df18edc5f44e2aa0b43a94615823b.pdf
    • https://cdn.shopify.com/s/files/1/0429/9712/1178/files/trizetto_facets_user_guide.pdf
    • https://cdn.shopify.com/s/files/1/0427/5005/0460/files/67213457481.pdf
    • https://cdn.shopify.com/s/files/1/0432/6552/3870/files/livro_compreendendo_o_behaviorismo.pdf
    • https://cdn.shopify.com/s/files/1/0429/2427/7927/files/behringer_x32_guide.pdf
    • https://cdn.shopify.com/s/files/1/0427/8901/1612/files/zilefekuligamivako.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_off00006b9e.bin
b81b4a688501ec2a0ad037519a46b3b0e2f06da7392a0249c5a51494a71df61f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B9E 5296 bytes
font_01_sfnt_off00007daa.bin
4eb70fdb773fd3db962557a97ee3ba866f78d538b188d660064820902f47e408
pdf-font-stream PDF embedded font (sfnt) at offset 0x7DAA 9956 bytes