Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55db856b54997f8…

MALICIOUS

PDF

39.9 KB Created: 2020-09-11 08:30:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ec8870bf14b57f2d2b151315e9ee5abf SHA-1: 8e0319bed180505a83456d8befb02a606128a7dc SHA-256: c55db856b54997f89c5abfe8b65c4e7d3bd5c8d175db66ade6de6edf1a16feb7
154 Risk Score

Malware Insights

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

The PDF file was flagged as malicious due to the presence of a link to a known malicious redirector. The document body, though heavily obfuscated, contains the URL that leads to this redirector. The file also contains a large number of embedded links, many pointing to static.usrfiles.com, which is identified as a link farm. The primary malicious indicator is the redirector URL, suggesting a phishing or malware delivery attempt.

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.club/wix?keyword=cork+sheet+cutting+machine
    • https://static.usrfiles.com/ugd/7ad284_ebe547a8eaeb4102b588e1780117887c.pdf
    • https://static.usrfiles.com/ugd/b8c837_a33d3cda790a4d43ba951291a5ab1ebf.pdf
    • https://static.usrfiles.com/ugd/98e2de_78077d9c47094d0f9b24de0f9d7548ca.pdf
    • https://cdn.shopify.com/s/files/1/0430/7773/0464/files/malayalam_kambikuttan_download.pdf
    • https://cdn.shopify.com/s/files/1/0449/8640/0936/files/lelosusibugivox.pdf
    • https://cdn.shopify.com/s/files/1/0431/1685/5457/files/54337792489.pdf
    • https://cdn.shopify.com/s/files/1/0429/2732/5343/files/vodolanimoxodiweguxagedak.pdf
    • https://cdn.shopify.com/s/files/1/0437/5655/2343/files/algebra_2_topical_review_book.pdf
    • https://static.usrfiles.com/ugd/d775a9_959b487b7939436fbf63d2c5fb6b9c54.pdf
    • https://static.usrfiles.com/ugd/b5aed9_79b3b39da71e47f2a8b3d623e3fec38e.pdf
    • https://static.usrfiles.com/ugd/974a4e_4f4f58fe6bee4360be3edea4f6e57179.pdf
    • https://static.usrfiles.com/ugd/b96e41_900b526260ca44b6808f49e6ada745dc.pdf
    • https://static.usrfiles.com/ugd/5899d5_5c742ec837f74a9686b9e7c0ee0c8485.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_off00005e45.bin
e3a41c99527fc66c2ef0ebdb10afb1ca2e51729075346da19268052860ac0877
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E45 5148 bytes
font_01_sfnt_off00006f9e.bin
66e6d261403b8ff8864e7e26ad825b567c7cce55fa1609d6853cf89cad6d797b
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F9E 10404 bytes