Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f7768a2bffb4949…

MALICIOUS

PDF

43.6 KB Created: 2020-09-05 04:35:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1809a0c82ff5768394c244a69c3efc0b SHA-1: 40baeeb187561466d39de1aaa49e03b6693fcdd4 SHA-256: 9f7768a2bffb49495b92b10a88fd2147e3011b93fd7560ce3788249821a7bb8d
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that appears to be the same as the one identified by the redirector heuristic. The presence of numerous other PDF links, many pointing to static.usrfiles.com, suggests a link farm or a method to obscure the ultimate destination. 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.me/pify?keyword=tamil+album+songs+free++kuttyweb
    • https://static.usrfiles.com/ugd/740d8c_9df6deaceaa14d26aabc7d216240b498.pdf
    • https://static.usrfiles.com/ugd/479fa9_ca68f88c610c4e11a8fe78b9c992ce7e.pdf
    • https://static.usrfiles.com/ugd/1ebe14_a4a4b7678c084dd1a220c3fa5b3df1c0.pdf
    • https://cdn.shopify.com/s/files/1/0435/1708/3802/files/jowoxejasofuferakaja.pdf
    • https://cdn.shopify.com/s/files/1/0431/8999/3636/files/gopobugegotoralojur.pdf
    • https://cdn.shopify.com/s/files/1/0434/9083/6645/files/15888513588.pdf
    • https://cdn.shopify.com/s/files/1/0439/1639/4648/files/43926891740.pdf
    • https://static.usrfiles.com/ugd/89064d_0d0cde4065c04f0a9c018eecd58a9307.pdf
    • https://static.usrfiles.com/ugd/824332_ba10fac100cc42bdac84914d485e9749.pdf
    • https://static.usrfiles.com/ugd/ce77c6_20fb920db52e4a199511950680b3e68a.pdf
    • https://static.usrfiles.com/ugd/d94ae5_533f76b50f8c4b248b6c932e774a58c2.pdf
    • https://static.usrfiles.com/ugd/b1b3ad_8a617a52b2354a9b92ee7338cd56c7b5.pdf
    • https://static.usrfiles.com/ugd/fd3290_58518253360946549db8a6b9a29fbd29.pdf
    • https://static.usrfiles.com/ugd/808d8c_0bc4ffdf6b2540108bde0e3aa2a6161d.pdf
    • https://static.usrfiles.com/ugd/8d0191_a868592fc6ba4c9d991a96421ce346fc.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_off000063e6.bin
b325bd61e327bd8745a7d8ec5c5c4d7434043257e2394dc03a50f07e1a055c3f
pdf-font-stream PDF embedded font (sfnt) at offset 0x63E6 5432 bytes
font_01_sfnt_off00007669.bin
69b6001285df44f75df917fd6c97b34a29cb49dc94b2317256b2326790b01133
pdf-font-stream PDF embedded font (sfnt) at offset 0x7669 12752 bytes