Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e3443d5895cbd35…

MALICIOUS

PDF

41.6 KB Created: 2020-08-30 05:56:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37011e8af624fa9b25f38b8faa7e8c87 SHA-1: fd86e787296d64eb13d8401c36a2924b9ecc0f9d SHA-256: 8e3443d5895cbd35082034180295ba171b3d9ce48a9c94c1ca7a297395d65848
152 Risk Score

Malware Insights

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

This PDF document contains a large number of embedded links, many of which point to external PDF files hosted on static.usrfiles.com, forming a link farm. One prominent link directs to ttraff.com, which is flagged as a malicious redirector. The document's content, though garbled, suggests a lure related to a 'periodic puzzle answer key'. The ML classifier strongly indicated maliciousness, supporting the conclusion that this PDF is designed to redirect users to malicious infrastructure.

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/wix?keyword=periodic+puzzle+answer+key
    • https://static.usrfiles.com/ugd/fd7405_c6d9812e261a49b0b7e72a541c68ab23.pdf
    • https://static.usrfiles.com/ugd/625844_51af9ee195d549599fb3b43df4fa260b.pdf
    • https://static.usrfiles.com/ugd/74c34a_af490262228e42b284fa4858f37094cb.pdf
    • https://static.usrfiles.com/ugd/5ad03d_67ea5358c19d4890bf6050668274c4e5.pdf
    • https://static.usrfiles.com/ugd/b8c837_463de93d2f4c4289be6300a96b299f5c.pdf
    • https://static.usrfiles.com/ugd/b8c837_7eb12e43ac1a4dfba1729cfb09986dba.pdf
    • https://static.usrfiles.com/ugd/3bf302_80cb9fa8e5d8499ea8dc0e4a50d478c2.pdf
    • https://static.usrfiles.com/ugd/b8c837_cd358dfc61e540668b4d35995bce5230.pdf
    • https://static.usrfiles.com/ugd/857e61_79b0f89642f945f9bb7423275e7db60d.pdf
    • https://static.usrfiles.com/ugd/b47706_e9c64b3f40744753a10401d1d1d14197.pdf
    • https://static.usrfiles.com/ugd/2c8d66_01c9c412005d43a6a996c86069e175ff.pdf
    • https://static.usrfiles.com/ugd/6908d7_22b363c86b2f497eb0e88df6caf3571f.pdf
    • https://static.usrfiles.com/ugd/b8c837_bad49abe751b4e6fbf4d31c8e0ebd9e1.pdf
    • https://static.usrfiles.com/ugd/a771bd_4270116450284aebb98a0c1694cadbce.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_off0000645d.bin
612952de03cd312f18ba3702760ac134f60a92073cc4dc6d76f660b3ca692ff6
pdf-font-stream PDF embedded font (sfnt) at offset 0x645D 5376 bytes
font_01_sfnt_off000076cb.bin
0ee231385211375ba9993d8785f47854ca2127745480eba7a2b302d7322cea57
pdf-font-stream PDF embedded font (sfnt) at offset 0x76CB 10228 bytes