Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef36f41da4fc0a21…

MALICIOUS

PDF

39.5 KB Created: 2020-08-30 11:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 39fb56dec44ad0763dd34677c63e9111 SHA-1: 6548f175c2592269d81966f354388a91be6d450a SHA-256: ef36f41da4fc0a21c68a26c308bd51ac52ccbbf1c9608163321c65c198404736
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the same URL found in the heuristics, suggesting it is the primary lure. The presence of numerous other PDF links, some pointing to benign Shopify domains, indicates a potential link farm or SEO poisoning attempt to mask the 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.cc/wix?keyword=grundig+yb400pe+ac+adapter
    • https://static.usrfiles.com/ugd/b8c837_ccb8a125ba5a459f8f601b6bfbbbc0f4.pdf
    • https://static.usrfiles.com/ugd/b8c837_114f6fa836b74e938d7a4e247ad61e08.pdf
    • https://static.usrfiles.com/ugd/e33828_b28b85155aa64658ac5e7d8af9201175.pdf
    • https://cdn.shopify.com/s/files/1/0432/9704/6681/files/ivoclar_vivadent_bleach_shade_guide.pdf
    • https://cdn.shopify.com/s/files/1/0436/1568/2717/files/tales_of_phantasia_rom.pdf
    • https://cdn.shopify.com/s/files/1/0431/0119/2352/files/tonamunitazed.pdf
    • https://cdn.shopify.com/s/files/1/0429/9109/1875/files/tiviti.pdf
    • https://cdn.shopify.com/s/files/1/0431/1564/3041/files/30439152160.pdf
    • https://cdn.shopify.com/s/files/1/0434/1517/5335/files/gezipibefawewamesim.pdf
    • https://cdn.shopify.com/s/files/1/0431/5820/8674/files/allopathy_in_tamil.pdf
    • https://cdn.shopify.com/s/files/1/0433/5537/3720/files/44528135528.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_off00005b30.bin
b5253d2dc8ab473e56831b5eb65184ed9a0b7795e82da82a5666e7938ca44fc9
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B30 5536 bytes
font_01_sfnt_off00006e15.bin
cae9670d8b26c0d121248278e614aaaae772c60e848dca9b0eee5fca50d4cde0
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E15 10420 bytes