Malicious PDF — malware analysis report

Static analysis result for SHA-256 22239e96f728e77f…

MALICIOUS

PDF

40.9 KB Created: 2020-08-30 07:42:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0819c8a6ec948512deff8e1594e376f9 SHA-1: ea67712b11769c146d382e5e8f055b51a149a550 SHA-256: 22239e96f728e77f480da2cff549b8bc03af35f969408e9493850ba7e8f02420
152 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector, ttraff.ru, which is disguised as exam answers. The document also hosts a large number of external PDF links, many pointing to static.usrfiles.com, suggesting a link farm or SEO poisoning tactic. The ML classifier strongly flagged this PDF as malicious. No scripts were extracted, but the primary attack vector appears to be social engineering via a deceptive document.

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=cisco+chapter+1-+6+checkpoint+exam+answers
    • https://static.usrfiles.com/ugd/b8c837_36b94304d93f40bca7dbe41b437efeb7.pdf
    • https://static.usrfiles.com/ugd/538d67_bc3f40cf8a9e44fa8b2ed6d0c7c84fe8.pdf
    • https://static.usrfiles.com/ugd/29c71c_29af8c3175fb478394bc32c07b48fc3d.pdf
    • https://static.usrfiles.com/ugd/c0b427_89d42b1a280d4bd8889dad43c5b2816a.pdf
    • https://static.usrfiles.com/ugd/b8c837_55ccc61bb7a942039f0ba64841579924.pdf
    • https://static.usrfiles.com/ugd/b8c837_4ce7df141ee543ad95be663f69fcede8.pdf
    • https://static.usrfiles.com/ugd/b8c837_90cbdfe5e4e44502bfc36b782c597e03.pdf
    • https://static.usrfiles.com/ugd/b8c837_256face7412840ebbca2064dbaf5c13f.pdf
    • https://static.usrfiles.com/ugd/d2751c_31e8308afbcf42aba17d800c5daf6622.pdf
    • https://static.usrfiles.com/ugd/b8c837_3f4f84a6a05a415fadeb236f94690782.pdf
    • https://cdn.shopify.com/s/files/1/0428/7044/0095/files/82366540907.pdf
    • https://cdn.shopify.com/s/files/1/0432/0005/3408/files/gebogej.pdf
    • https://cdn.shopify.com/s/files/1/0438/9725/8136/files/durable_power_of_attorney_form_ny.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/
    • https://static.usrfiles.com/ugd/b8c837_256face74128

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006255.bin
99910289fc3684b9d71b890d3ab29d921c2da75dca0270452a10821971f1389a
pdf-font-stream PDF embedded font (sfnt) at offset 0x6255 5508 bytes
font_01_sfnt_off00007504.bin
adb5db06c46177b0c80af88aec2b8be8f8aef38f759a10d83e8f9e2214889a08
pdf-font-stream PDF embedded font (sfnt) at offset 0x7504 9844 bytes