Malicious PDF — malware analysis report

Static analysis result for SHA-256 390c4b0d241d4c88…

MALICIOUS

PDF

44.4 KB Created: 2020-09-01 05:10:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ce0900d16a710ad5de37659561095c23 SHA-1: 9257bdba3ea8defc75e68da23340dad4e0ad6c7b SHA-256: 390c4b0d241d4c8838b1a17aab0f7b5c29f3b3c46cec551fae0f248610587d5a
152 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector, ttraff.cc, which is disguised as a worksheet. The ML classifier strongly indicated maliciousness. The document body, though heavily obfuscated, contains the malicious URL and references to other PDFs hosted on static.usrfiles.com, suggesting a link farm or content distribution network used for the attack.

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=worded+simultaneous+equations+worksheet+pdf
    • https://static.usrfiles.com/ugd/b8c837_0101ef8a9c1742d981a7ea29c01fd187.pdf
    • https://static.usrfiles.com/ugd/b8c837_963a1f0ead924d0b943671f60847e9cf.pdf
    • https://static.usrfiles.com/ugd/5438e3_dd35a6210e904a248458dd83a375f0a2.pdf
    • https://static.usrfiles.com/ugd/b7082a_78beb4e708d34af891be376993978098.pdf
    • https://static.usrfiles.com/ugd/b28561_549467e4c57f49fe935e0534a50353b0.pdf
    • https://static.usrfiles.com/ugd/b8c837_9431dcffb636424b802f7aac8940d8e2.pdf
    • https://static.usrfiles.com/ugd/ce14f3_f36b323d8a7b440b873e83931d05f86f.pdf
    • https://static.usrfiles.com/ugd/b98abb_3ba1998f4cd14f589b8a439bea01e897.pdf
    • https://cdn.shopify.com/s/files/1/0434/5289/1298/files/xuragajejotebegesilejak.pdf
    • https://cdn.shopify.com/s/files/1/0437/5946/8701/files/34358883105.pdf
    • https://cdn.shopify.com/s/files/1/0430/9798/1089/files/46241097806.pdf
    • https://cdn.shopify.com/s/files/1/0437/7880/1822/files/cohesion_lexica_y_pronominal.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005e71.bin
a85e6c7e54672fa950aff51bea9ebcb1fec636ba86744e5df48ffab7cef832d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E71 5456 bytes
font_01_sfnt_off000070e3.bin
d5b1348c0c4d3b4a4d1389afe7f17c1444d08002ef0cd69553c48c96e4b336ca
pdf-font-stream PDF embedded font (sfnt) at offset 0x70E3 11160 bytes
font_02_sfnt_off000096b5.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x96B5 4324 bytes