Malicious PDF — malware analysis report

Static analysis result for SHA-256 ffd081fa9d876b62…

MALICIOUS

PDF

44.2 KB Created: 2020-09-01 20:54:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d520f3f20d27acc9f5b40b28972e09c8 SHA-1: bf38f6ef92a911e54605f3798900b2d4a89df6d2 SHA-256: ffd081fa9d876b62388e91c6e0fdb50599aac11be215967dc0e8bd72cf1cd08b
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a significant number of embedded links. One critical heuristic identified a link to a known malicious redirector infrastructure at 'https://ttraff.com/wix?keyword=latex+template+formal+letter'. Another heuristic indicated a PDF link farm, with many links pointing to 'static.usrfiles.com'. The document body, though heavily obfuscated, also contains the URL 'https://ttraff.com/wix?keyword=latex+template+formal+letter' and several URLs from 'static.usrfiles.com'. This suggests a phishing or malware distribution attempt leveraging a link farm to obscure the final malicious destination.

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=latex+template+formal+letter
    • https://static.usrfiles.com/ugd/d2cc1f_706a344492694d7cbed5644cfe0d4f37.pdf
    • https://static.usrfiles.com/ugd/b8c837_d2a1fcf02e7b413fa64c9be161872fc0.pdf
    • https://static.usrfiles.com/ugd/69b86f_04b28c47b106400194cc06083b13f6ce.pdf
    • https://static.usrfiles.com/ugd/4dd980_2795b86b2fad4999a1adc1569d0431c8.pdf
    • https://static.usrfiles.com/ugd/52b593_8ca27c11a70e492190e2843e2c6fe0d3.pdf
    • https://static.usrfiles.com/ugd/80bfa9_67317bb9afb6420fa8769a2e141e00ca.pdf
    • https://static.usrfiles.com/ugd/07ef24_2230d7bf912d42a6933c016e625d7e1c.pdf
    • https://cdn.shopify.com/s/files/1/0428/6241/1942/files/zafowuxenegejoxasir.pdf
    • https://cdn.shopify.com/s/files/1/0432/4343/8242/files/mimagenujazewe.pdf
    • https://static.usrfiles.com/ugd/7ff653_09b8ee274dff4028bdedfe5048e827aa.pdf
    • https://static.usrfiles.com/ugd/63022f_0ba5e257695a4148ae753cacb35c11f7.pdf
    • https://static.usrfiles.com/ugd/b8c837_496c8eb36ba64e1a8770a0d32e39d74c.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_off00006df7.bin
bfcc07b66d5a4426d87a1f2a0ccd929b7f679e680cf89a5e5e512c4a281f4ece
pdf-font-stream PDF embedded font (sfnt) at offset 0x6DF7 4876 bytes
font_01_sfnt_off00007e86.bin
755158bcd5ccd76667fd65a09a3f8986256fb53c99b3a0625fd79937e7d56842
pdf-font-stream PDF embedded font (sfnt) at offset 0x7E86 11048 bytes