Malicious PDF — malware analysis report

Static analysis result for SHA-256 e28ad84f4b1c48d8…

MALICIOUS

PDF

38.6 KB Created: 2020-08-14 05:01:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cd94cb0c40e74c4cf0e9de97a5f2dd21 SHA-1: bf3ca7f831552e41754daabcdaedb62504a06e00 SHA-256: e28ad84f4b1c48d882671772e9285a995f02b585a545caeca9d02d9ff880509d
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded links, many of which point to a link farm hosted on Shopify. One prominent link, 'https://ttraff.com/wb?keyword=multiple%20worksheet%20in%20excel%20definition', is flagged as a malicious redirector. The document body, though heavily obfuscated, also contains this URL, suggesting a lure to a malicious site. The ML classifier strongly supports the malicious nature of this PDF.

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.com/wb?keyword=multiple%20worksheet%20in%20excel%20definition
    • http://rimog.virginiashowmasterscircuit.com/uploads/1/3/1/1/131164250/biralafakogom.pdf
    • http://files.dwpguitars.com/uploads/1/3/1/4/131453136/e5d29.pdf
    • http://files.draincareseptic.com/uploads/1/3/0/7/130739525/radunox.pdf
    • https://cdn.shopify.com/s/files/1/0430/4257/0402/files/bizitufujarufelebanak.pdf
    • https://cdn.shopify.com/s/files/1/0429/7555/9829/files/central_limit_theorem_examples_with_solutions.pdf
    • https://cdn.shopify.com/s/files/1/0438/0291/9074/files/vaduxepisisajofak.pdf
    • https://cdn.shopify.com/s/files/1/0430/9748/9572/files/malugonetuvogowixurope.pdf
    • https://cdn.shopify.com/s/files/1/0435/8835/4207/files/41180951601.pdf
    • https://cdn.shopify.com/s/files/1/0433/9066/4860/files/dozaf.pdf
    • https://cdn.shopify.com/s/files/1/0439/5725/6350/files/sulowojutixewu.pdf
    • https://cdn.shopify.com/s/files/1/0437/7870/3521/files/86236235579.pdf
    • https://cdn.shopify.com/s/files/1/0431/3563/1514/files/16854657858.pdf
    • https://cdn.shopify.com/s/files/1/0434/1596/1762/files/82638884448.pdf
    • https://cdn.shopify.com/s/files/1/0439/1501/8392/files/waiting_for_godot_file.pdf
    • https://cdn.shopify.com/s/files/1/0437/4292/0869/files/all_in_one_checker.pdf
    • https://cdn.shopify.com/s/files/1/0435/2226/1143/files/soken.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_off00005a56.bin
5acd4c7ac47dd1a3d1bac03645c767fdb857247a0e2f922eb7ef90f001e3336b
pdf-font-stream PDF embedded font (sfnt) at offset 0x5A56 5260 bytes
font_01_sfnt_off00006c54.bin
91faaac7c6067a5275a31c82b75f65132f0783638df224ec88ae0856c15daa07
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C54 9704 bytes