Malicious PDF — malware analysis report

Static analysis result for SHA-256 bdb365c916dd96df…

MALICIOUS

PDF

41.4 KB Created: 2020-08-29 15:55:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0b2df38580d21a543ae5191dc8d493da SHA-1: de9ec537a615845c2f70098ecbec03935fd824d9 SHA-256: bdb365c916dd96df11a7e7179f10e6d21a23317208c4eeaed7e1ecd881d19b45
152 Risk Score

Malware Insights

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

The PDF contains a link farm designed to appear as legitimate downloads, but the primary link redirects to malicious infrastructure. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms this, and the ML classifier strongly supports a malicious verdict. The document body, though heavily obfuscated, contains the malicious URL and references to textbook downloads, indicating a social engineering lure.

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=algebra+2+textbook+pdf+download
    • https://static.usrfiles.com/ugd/eda9ba_f7bbf8e9c9904cb590def5ec8ab35219.pdf
    • https://static.usrfiles.com/ugd/b8c837_4c6641363833409b82816d758d0509e3.pdf
    • https://static.usrfiles.com/ugd/b8c837_ca7214c10c1b47438db081708e9ff2ce.pdf
    • https://cdn.shopify.com/s/files/1/0433/7421/5331/files/88339454897.pdf
    • https://cdn.shopify.com/s/files/1/0440/8908/2006/files/manuel_belgrano_biografia.pdf
    • https://cdn.shopify.com/s/files/1/0430/4296/3613/files/64829652364.pdf
    • https://cdn.shopify.com/s/files/1/0429/2483/4982/files/informacion_del_aguila_real_en_ingles.pdf
    • https://cdn.shopify.com/s/files/1/0431/7190/5698/files/26493699916.pdf
    • https://cdn.shopify.com/s/files/1/0429/9633/4753/files/operations_management_11th_edition_heizer.pdf
    • https://cdn.shopify.com/s/files/1/0437/3066/5637/files/gijapaziwofigaxezesexovop.pdf
    • https://cdn.shopify.com/s/files/1/0435/4169/2580/files/bible_study_materials_in_tamil.pdf
    • https://cdn.shopify.com/s/files/1/0439/8638/7102/files/landscape_architectural_design_and_construction_technology.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_off000061db.bin
c81adee74eed3f86608412ce083ff27c8c5463ab618dc9cb6affd8539afa70ba
pdf-font-stream PDF embedded font (sfnt) at offset 0x61DB 5516 bytes
font_01_sfnt_off000074d2.bin
3dccbb4d9a2d82ee32857c437f996ec1c35136bee8fc38d41284d93149ee49c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x74D2 10532 bytes