Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b33d9fc41f9e4f1…

MALICIOUS

PDF

113.4 KB Created: 2020-09-03 07:02:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d04520ca4bfae8914ef22b6b6f9345c6 SHA-1: d81ed26d74c3e1dc25fcace2393912fa08cafc5e SHA-256: 4b33d9fc41f9e4f1b51694598f1184f8560c80d761e98be7f6e8ad5f3e64abbe
152 Risk Score

Malware Insights

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

The PDF contains a prominent link that redirects to a URL associated with malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to tax forms, suggesting a phishing lure. The ML classifier strongly indicated maliciousness, and the PDF structure includes a link farm, further supporting a malicious intent.

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=1040+itemized+deductions+worksheet+2018
    • https://static.usrfiles.com/ugd/b8c837_35f541860a7a4d03b64aaf45e2b94f5f.pdf
    • https://static.usrfiles.com/ugd/77d535_99bb51b4c8bc4f7bb944f28a28ca4ad8.pdf
    • https://static.usrfiles.com/ugd/bcd086_a69b1690559c4b20bb0ae4faa0c43970.pdf
    • https://static.usrfiles.com/ugd/111c46_34618947016f4e5592d053ca2fa8fff8.pdf
    • https://cdn.shopify.com/s/files/1/0429/1638/0831/files/53035283725.pdf
    • https://cdn.shopify.com/s/files/1/0427/5788/2022/files/serodude.pdf
    • https://cdn.shopify.com/s/files/1/0458/5511/3369/files/vutolabinupeguwunuron.pdf
    • https://static.usrfiles.com/ugd/9fc8c3_b61b9a74643b48bc97a576e7b6dedd11.pdf
    • https://static.usrfiles.com/ugd/d5cf39_c320bc5f8ba3429b977d02a01329a8d2.pdf
    • https://static.usrfiles.com/ugd/b8c837_1fdf750a5d634e91aaa69aba65daef50.pdf
    • https://static.usrfiles.com/ugd/b8c837_09a1505ba1864445ae4780b5e3ee6aca.pdf
    • https://cdn.shopify.com/s/files/1/0437/8332/3806/files/kingsman_the_secret_service_full_movie_download.pdf
    • https://cdn.shopify.com/s/files/1/0435/3160/0031/files/alvin_and_the_chipmunks_songs.pdf
    • https://cdn.shopify.com/s/files/1/0436/3055/9390/files/gefeduzoxa.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_off000175dc.bin
a174769a90c122d03ca6f020ba7c5dcdbc75496f01a750ce9646b0f3702e0169
pdf-font-stream PDF embedded font (sfnt) at offset 0x175DC 5656 bytes
font_01_sfnt_off0001891f.bin
4ef1ca158a5bb5d561b8efe997acdf43f9cf5a2d7d1878f563ca33a2790b44f1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1891F 14964 bytes