Malicious PDF — malware analysis report

Static analysis result for SHA-256 d91a28b985753507…

MALICIOUS

PDF

40.0 KB Created: 2020-08-15 18:08:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2b016936fce463a576c2d0a622b56352 SHA-1: 1df578146b74790983abc278129564ff0c872fb2 SHA-256: d91a28b985753507b0a77c595e8994d7d037bbc698aa58a482e3f6d7deee87f7
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one heuristic specifically identifying a malicious redirector. The document body, though heavily obfuscated, contains text and URLs that appear to be part of a link farm designed to drive traffic to malicious sites. The ML classifier strongly indicated maliciousness, supporting the conclusion that this PDF is used for malicious redirection.

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/wb?keyword=pdf%20fotosintesis%20tumbuhan
    • http://sekuw.thirdshotdrop.ca/uploads/1/3/1/3/131383483/7023424.pdf
    • http://files.fromtherib.org/uploads/1/3/1/6/131637135/6220637.pdf
    • http://files.columbianacoc.com/uploads/1/3/1/6/131637163/8c35b74b.pdf
    • http://files.researchcubaneducation.com/uploads/1/3/0/9/130969179/5205860.pdf
    • https://cdn.shopify.com/s/files/1/0432/2469/4942/files/61354139207.pdf
    • https://cdn.shopify.com/s/files/1/0434/2366/2236/files/vizazulekedebometew.pdf
    • https://cdn.shopify.com/s/files/1/0437/8745/2576/files/32865820107.pdf
    • https://cdn.shopify.com/s/files/1/0429/8709/4177/files/andrew_ng_machine_learning_book.pdf
    • https://cdn.shopify.com/s/files/1/0427/4028/5607/files/87205408217.pdf
    • https://cdn.shopify.com/s/files/1/0434/4047/2229/files/53877428037.pdf
    • https://cdn.shopify.com/s/files/1/0433/7932/7130/files/20300292454.pdf
    • https://cdn.shopify.com/s/files/1/0439/1682/0635/files/la_cantatrice_chauve_scne_7.pdf
    • https://cdn.shopify.com/s/files/1/0434/2274/4741/files/52017660581.pdf
    • https://cdn.shopify.com/s/files/1/0432/1017/8717/files/32145120392.pdf
    • https://cdn.shopify.com/s/files/1/0430/7091/4717/files/super_mario_ps3_game.pdf
    • https://cdn.shopify.com/s/files/1/0435/4415/0165/files/aridity_index.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_off00006086.bin
ab89ebfbbb79c6a087a98aea233d2ed31b34c89f4515108ce76b94cc0a6a5506
pdf-font-stream PDF embedded font (sfnt) at offset 0x6086 5160 bytes
font_01_sfnt_off000071e4.bin
48b8dce394f9e5758c3a0673c2253a6f48bc723600550d6103c8b64e895cd374
pdf-font-stream PDF embedded font (sfnt) at offset 0x71E4 9804 bytes