Malicious PDF — malware analysis report

Static analysis result for SHA-256 acdbc8a54ae3f229…

MALICIOUS

PDF

36.4 KB Created: 2020-08-30 17:48:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 214a422382006c78e2c78acddfca9f45 SHA-1: 6540888185457e22b534440cfea2c75fe4197f98 SHA-256: acdbc8a54ae3f2295ce1ef3284087480e3bc2a0f7f593a59757aa35d37226304
154 Risk Score

Malware Insights

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

The PDF file contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.cc/wix?keyword=sujeto+y+predicado+ejercicios+primar'. Additionally, it exhibits characteristics of a PDF link farm, with numerous embedded links to external PDFs, many hosted on 'static.usrfiles.com'. The ML classifier also strongly flagged this PDF as malicious. The document body, though partially obfuscated, contains the malicious URL and references to other PDFs, suggesting a lure to external content that likely leads to further malicious activity.

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=sujeto+y+predicado+ejercicios+primar
    • https://static.usrfiles.com/ugd/d17951_2ab10d23b6ef4f3e849b9dd47d5023dc.pdf
    • https://static.usrfiles.com/ugd/289c5e_04fad8c0c85445a9951530c96d2e99f5.pdf
    • https://static.usrfiles.com/ugd/99965f_bf3b7154715c40e3bd13342c0d9a5433.pdf
    • https://static.usrfiles.com/ugd/b8c837_77394d6477be4f16a210ad4efedf8936.pdf
    • https://static.usrfiles.com/ugd/3b47cb_3f7a28b92a114f4cb15418c9524e1ad3.pdf
    • https://static.usrfiles.com/ugd/6924eb_a142a1739c874c3785865436da61fd9b.pdf
    • https://static.usrfiles.com/ugd/b8c837_44d1d516be284407893d7fb00f95a00c.pdf
    • https://static.usrfiles.com/ugd/b8c837_2a6ee4b485994e83a8f61d18f6b92ae3.pdf
    • https://static.usrfiles.com/ugd/cac9e4_441ae8dd4f2e4e3ea6cf178a911c678e.pdf
    • https://static.usrfiles.com/ugd/b8c837_c0752d5577b0454d9f1fb8dbe0129a5c.pdf
    • https://static.usrfiles.com/ugd/b8c837_115a7a9572aa4889834bfac29b25440c.pdf
    • https://static.usrfiles.com/ugd/b8c837_f08824529f9b4738bcc0c7db2681c5c1.pdf
    • https://static.usrfiles.com/ugd/1b8612_8549849f73ec41f5be6480e07e00a82e.pdf
    • https://static.usrfiles.com/ugd/69b86f_0fecfb95649a4a41ba91539f2f004bec.pdf
    • https://static.usrfiles.com/ugd/b8c837_7833f64966f34f469fad80d53459a300.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_off00004d94.bin
b344e38212c0c712dd973169fdb5edf6be8a8ad9dca1f3e4d7c2f670d6ef9691
pdf-font-stream PDF embedded font (sfnt) at offset 0x4D94 5468 bytes
font_01_sfnt_off00006025.bin
4966787771799095ff7056ee1bd481532d12b6b9b78435def30228d55e5f8e1f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6025 10812 bytes