Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d9f3a6a43fe0c87…

MALICIOUS

PDF

40.5 KB Created: 2020-08-01 06:20:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc8931b930dab62e110a12223ec57f76 SHA-1: b3d41d1705df211b32d1eaf4c279cdad968bc26f SHA-256: 5d9f3a6a43fe0c87d2136a0685478de27698ece30c00afafcca22462bfed9d2e
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with one identified as a malicious redirector. The document body, though heavily obfuscated, contains text related to a 'Wonderlic scholastic level exam' and the authoring application 'wkhtmltopdf', suggesting a lure to trick users into clicking the malicious link. 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.ru/pify?keyword=wonderlic+scholastic+level+exam
    • http://files.blackandpetrichor.com/uploads/1/3/1/8/131872021/d428aa125.pdf
    • http://files.michelleaoates.com/uploads/1/3/0/7/130739542/bdfc3e21bb.pdf
    • http://files.susanstandfield.com/uploads/1/3/1/4/131408537/9efd7c8b1c.pdf
    • http://files.pixiedustexpert.com/uploads/1/3/1/4/131453565/xunodasev-wijunaze-juzuzutep-vamividip.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0430/9463/8749/files/welamuwupuwaxoz.pdf
    • https://cdn.shopify.com/s/files/1/0434/2258/0886/files/28908461844.pdf
    • https://cdn.shopify.com/s/files/1/0429/2709/5967/files/komofa.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/jufozigazagapuji.pdf
    • https://cdn.shopify.com/s/files/1/0434/5744/6038/files/11283368825.pdf
    • https://cdn.shopify.com/s/files/1/0437/5255/4657/files/juvizon.pdf
    • https://cdn.shopify.com/s/files/1/0430/0505/1029/files/90102255169.pdf
    • https://cdn.shopify.com/s/files/1/0439/4637/7374/files/77025314381.pdf
    • https://cdn.shopify.com/s/files/1/0433/5537/3720/files/8446104366.pdf
    • https://cdn.shopify.com/s/files/1/0430/8677/4436/files/xewonugezixifuxazoxejufi.pdf
    • https://cdn.shopify.com/s/files/1/0437/1021/8391/files/61737509966.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/41758367329.pdf
    • https://cdn.shopify.com/s/files/1/0433/9240/1573/files/dobevedupazubutig.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000060d5.bin
a289d5be8b71f89a39d60ab2f7b26aa437bc47f849ac55a35a6809f5aab2f9ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x60D5 5320 bytes
font_01_sfnt_off000072d1.bin
309563521b1e4f47993ad5d36419cafa76f818a2adad63c17b123fec83a1a91e
pdf-font-stream PDF embedded font (sfnt) at offset 0x72D1 9984 bytes