Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ba52bf9cf8f5e58…

MALICIOUS

PDF

66.9 KB Created: 2020-08-05 10:30:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f154fdf1e0be1c51b51b197ebf3518cd SHA-1: 0fcafe3690e7435b5be70c866af2358be759d90c SHA-256: 4ba52bf9cf8f5e58433f78e454d4e00be6a3c61e45f18575081d8631fc1bcb25
152 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external PDF files, with one critical link identified as a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains URLs that are likely part of the redirection chain. The primary attack pattern involves luring users to click on these links, which then lead to malicious infrastructure.

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=internalization+theory+pdf
    • http://files.littlepiecesofart.co.uk/uploads/1/3/2/6/132681488/7878936.pdf
    • http://files.sbph.ca/uploads/1/3/1/3/131382032/wegeritibikuvevuta.pdf
    • http://files.gdshub.com/uploads/1/3/0/7/130739238/kusowiderozexuguxelo.pdf
    • http://files.musicinnarchives.org/uploads/1/3/2/7/132711975/1148969.pdf
    • https://cdn.shopify.com/s/files/1/0431/0378/1015/files/93741143512.pdf
    • https://cdn.shopify.com/s/files/1/0434/4614/1093/files/mutated_bloodveld_osrs.pdf
    • https://cdn.shopify.com/s/files/1/0433/4646/0840/files/39937844998.pdf
    • https://cdn.shopify.com/s/files/1/0432/9455/6324/files/sevezitozuvi.pdf
    • https://cdn.shopify.com/s/files/1/0427/9740/0223/files/62563771314.pdf
    • https://cdn.shopify.com/s/files/1/0434/4355/2416/files/kewowubinawifamoleto.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/pesaveput.pdf
    • https://cdn.shopify.com/s/files/1/0436/4288/0160/files/nekepowarudejozogejor.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/99839510681.pdf
    • https://cdn.shopify.com/s/files/1/0431/5699/6247/files/10056986340.pdf
    • https://cdn.shopify.com/s/files/1/0429/5183/5801/files/rufimafajozivu.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_off0000ca0f.bin
0856f876030baffeb7fa2891c58ad3b9a15a91d48ae3473119fa4c8796616bca
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA0F 5040 bytes
font_01_sfnt_off0000db40.bin
b66cf695625a0b634e6569b89257cf9df9bcfceca887093c1faa8496141ce2cf
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB40 10496 bytes