Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5a8ec161410cff…

MALICIOUS

PDF

55.8 KB Created: 2020-08-07 08:30:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 21674754d8bf6f51421df78baac65a13 SHA-1: 8cb11c488dd264e7f1a7a4451b1eacbaade9accf SHA-256: cf5a8ec161410cff05f0a38d4b7099ea7dee28fc80ea118118453eba2023d7d9
154 Risk Score

Malware Insights

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

The PDF contains a link farm designed to mimic search results for job vacancies, with the primary link redirecting to malicious infrastructure. The ML classifier strongly indicated maliciousness, and the PDF structure itself points to a link farm. The document body, though heavily obfuscated, contains the URL https://ttraff.ru/pify?keyword=casual+vacancy+book+pdf, which is flagged as a malicious redirector.

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/pify?keyword=casual+vacancy+book+pdf
    • http://files.tworiversreserve.org/uploads/1/3/1/3/131379832/darexij_wofebejeteniro_rijoxusofudibir.pdf
    • http://files.tarahanish.com/uploads/1/3/0/9/130969699/ddba46b93697.pdf
    • http://files.premierdanes.com/uploads/1/3/1/8/131859042/nawalefolenekuli.pdf
    • https://cdn.shopify.com/s/files/1/0434/7609/1046/files/rrb_allahabad_alp_result_2020.pdf
    • https://cdn.shopify.com/s/files/1/0428/5746/3971/files/2007_dodge_caliber_owner_s_manual.pdf
    • https://cdn.shopify.com/s/files/1/0436/1207/8243/files/61659187957.pdf
    • https://cdn.shopify.com/s/files/1/0432/3203/4980/files/fotikegatorojiwabizivin.pdf
    • https://cdn.shopify.com/s/files/1/0438/1832/0034/files/nubibolupazurufekaril.pdf
    • https://cdn.shopify.com/s/files/1/0431/2629/2629/files/vozesefudibiz.pdf
    • https://cdn.shopify.com/s/files/1/0436/1093/1358/files/bopasikewilorapuxazogixi.pdf
    • https://cdn.shopify.com/s/files/1/0429/9423/7599/files/samurai_shodown_64.pdf
    • https://cdn.shopify.com/s/files/1/0446/7766/0825/files/electrolysis_of_seawater.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_off00009da9.bin
1682c1ca673a7a419705c9f3a53be013cb769f33eee85731dbad5c6edb7bb2b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x9DA9 5324 bytes
font_01_sfnt_off0000afe4.bin
c91e9cedc054a22a343dcd5e6ab451ef82e6e20664a8c014d3c68f830bfc65e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xAFE4 10256 bytes