Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3c7b1fa3271cb2a…

MALICIOUS

PDF

40.9 KB Created: 2020-09-07 13:06:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ddd49dbeb9aa0f1c6ce2e946e9861c71 SHA-1: f3b06ce4f260ebe7a9b5aeba593c770b32c9f5a5 SHA-256: a3c7b1fa3271cb2aae0e3270ccf2d5077b6d7c6a0aad411201a99fa5d7cc35ca
152 Risk Score

Malware Insights

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

The PDF file contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.link/wix?keyword=audacity+manual+noise+reduction'. This URL is designed to lure users into clicking by appearing to offer relevant information. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the same redirector URL and a large number of other URLs, many hosted on 'static.usrfiles.com', suggesting a link farm or redirection strategy.

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.link/wix?keyword=audacity+manual+noise+reduction
    • https://static.usrfiles.com/ugd/3f80ec_dfe5728b5a184948b3f9dd52d797617a.pdf
    • https://static.usrfiles.com/ugd/e2b09b_0d800a697c3c4363b0fa0eee21af1a57.pdf
    • https://static.usrfiles.com/ugd/5ed537_f6ccd90a308247edb24ac1a8002a0854.pdf
    • https://static.usrfiles.com/ugd/f2c1dc_1b8847891b664c8da3084b5247aad6db.pdf
    • https://static.usrfiles.com/ugd/cf79db_aef666c06b594d68815ceb25a56e4362.pdf
    • https://cdn.shopify.com/s/files/1/0440/2846/1206/files/reset_google_password_on_android_phone.pdf
    • https://cdn.shopify.com/s/files/1/0438/4414/1218/files/assassin_s_creed_2_songs.pdf
    • https://static.usrfiles.com/ugd/0a593f_178f4e3b52c84661ad7574f435634313.pdf
    • https://static.usrfiles.com/ugd/b8c837_c0812bb7e82e41c58e9700235dc98bac.pdf
    • https://static.usrfiles.com/ugd/ea5d7b_0762fef49589470f8924d6c70479ee63.pdf
    • https://static.usrfiles.com/ugd/9ec29b_2873d20736324fd08398eac0e84942f5.pdf
    • https://cdn.shopify.com/s/files/1/0431/8419/3697/files/79670112264.pdf
    • https://cdn.shopify.com/s/files/1/0432/8692/1374/files/82889873493.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_off000062dc.bin
aee418eec696da1017c33c4168c57b03e2ab3154aa4690f372dbd81069934db0
pdf-font-stream PDF embedded font (sfnt) at offset 0x62DC 5176 bytes
font_01_sfnt_off00007469.bin
f96c5cfb71b67b3c8dd77d1c35ce7fac3f1b479e0745e2af056816dfa281fe15
pdf-font-stream PDF embedded font (sfnt) at offset 0x7469 9956 bytes