Malicious PDF — malware analysis report

Static analysis result for SHA-256 328f45cc9c72537c…

MALICIOUS

PDF

43.3 KB Created: 2020-08-03 15:27:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2cd0492922731c7ef81f0ef4dbb860e3 SHA-1: ef23ee629a7a0195bc7ed01770c484d984ba9dec SHA-256: 328f45cc9c72537c1e9432b67cb1b73dea959a08cf5b18ddb7582b46ed24283b
152 Risk Score

Malware Insights

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

The PDF contains a prominent link that redirects to a malicious URL, disguised with a seemingly relevant keyword. The ML classifier strongly indicated maliciousness, and the PDF structure itself is flagged for containing a mass external PDF link farm, suggesting a spam or SEO poisoning campaign. The primary malicious IOC is the redirector URL.

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/pify?keyword=brookfield+viscometer+procedure+pdf
    • http://files.holisticbynonala.com/uploads/1/3/0/8/130874281/3160331.pdf
    • http://files.davidbuiles.com/uploads/1/3/1/0/131071067/lewakerigejige.pdf
    • http://files.shannondrhodes.com/uploads/1/3/0/8/130873907/1944747.pdf
    • http://files.chandao.co.uk/uploads/1/3/0/8/130814902/bonapawujowi.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/jezimix.pdf
    • https://cdn.shopify.com/s/files/1/0438/2910/0701/files/2992828605.pdf
    • https://cdn.shopify.com/s/files/1/0437/4334/6839/files/bopexopuz.pdf
    • https://cdn.shopify.com/s/files/1/0441/2240/7064/files/tozerelibana.pdf
    • https://cdn.shopify.com/s/files/1/0434/6429/4557/files/vavub.pdf
    • https://cdn.shopify.com/s/files/1/0433/9702/1854/files/70580735615.pdf
    • https://cdn.shopify.com/s/files/1/0430/6750/6849/files/nukawomerimexuzi.pdf
    • https://cdn.shopify.com/s/files/1/0431/1698/6534/files/the_walking_dead_season_6_123movies.pdf
    • https://cdn.shopify.com/s/files/1/0435/8710/9023/files/4304863745.pdf
    • https://cdn.shopify.com/s/files/1/0434/0455/8488/files/70979510713.pdf
    • https://cdn.shopify.com/s/files/1/0433/4888/5662/files/gulorovezoti.pdf
    • https://cdn.shopify.com/s/files/1/0429/5573/5193/files/cribbage_against_jake.pdf
    • https://cdn.shopify.com/s/files/1/0436/7260/0726/files/kojupomos.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_off00006a1c.bin
248cdaec74a5cda68ec0517786461f623e2f2a7b4573096f41fb381351e843c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A1C 5264 bytes
font_01_sfnt_off00007c06.bin
1c6d4ba2ab4fa8cf91a4df8150351e15bde7057bcd810ed1e1c6a1580f901034
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C06 10692 bytes