Malicious PDF — malware analysis report

Static analysis result for SHA-256 b35e77375a5d732d…

MALICIOUS

PDF

53.2 KB Created: 2020-08-14 22:40:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 36de587b11a8592df07ac3cc10f28c8c SHA-1: 7320a63cfa266c2d10e71711c6bbb398e2abcf96 SHA-256: b35e77375a5d732d317e49f6af49e389cfa785e894c84c8a0ec78d3663831778
152 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains references to the malicious URL and a large number of external PDF links, suggesting a link farm or redirection attempt. The ML classifier also strongly indicated maliciousness.

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/wb?keyword=hypoxic%20hypoxia%20pdf
    • http://files.mickeytheis.com/uploads/1/3/1/3/131383467/zovitosovusizogebe.pdf
    • http://files.farmhousefixer.com/uploads/1/3/0/9/130969825/9341588.pdf
    • https://cdn.shopify.com/s/files/1/0432/9455/6324/files/job_application_letter_format_for_teacher.pdf
    • https://cdn.shopify.com/s/files/1/0430/9919/3501/files/vuziwenozugiwodelepuwitub.pdf
    • https://cdn.shopify.com/s/files/1/0434/6878/3768/files/sidofegipuzavazimurude.pdf
    • https://cdn.shopify.com/s/files/1/0431/1865/7697/files/26316473451.pdf
    • https://cdn.shopify.com/s/files/1/0431/1865/7697/files/buzukemupopu.pdf
    • https://cdn.shopify.com/s/files/1/0430/7773/0455/files/68605491815.pdf
    • https://cdn.shopify.com/s/files/1/0429/8578/3447/files/dividing_rational_numbers_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0440/8947/5237/files/fuwoguxesow.pdf
    • https://cdn.shopify.com/s/files/1/0429/3902/3526/files/75226388765.pdf
    • https://cdn.shopify.com/s/files/1/0432/8266/1526/files/42450466589.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_off00009193.bin
889f79a88d018639b17cf9894e2f2da3b40bf0e0a37ddcfc3947a48fa55a3cb4
pdf-font-stream PDF embedded font (sfnt) at offset 0x9193 5068 bytes
font_01_sfnt_off0000a2d2.bin
e0fb1e243a168dd4778b8bb1997d648971c10c6b0a4232f932522dce8958943d
pdf-font-stream PDF embedded font (sfnt) at offset 0xA2D2 11432 bytes