Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb4ff6e3b0e49efb…

MALICIOUS

PDF

41.4 KB Created: 2020-08-30 23:22:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c4a95e73883f2a45a359b14bbea163f8 SHA-1: 6c20c2f27d8f45b2f61f3e7f202c0ccd999537a6 SHA-256: cb4ff6e3b0e49efb7085eaf66e06a391c5641fec0dff66d2dbd2662c5709a604
152 Risk Score

Malware Insights

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

The PDF file contains a heuristic firing for a malicious redirector link, pointing to 'https://ttraff.cc/wix?keyword=oraciones+copulativas+y+predicativas+ejercicios+resueltos+pdf'. The document body, though heavily obfuscated, also contains this URL and numerous other links to PDF files hosted on 'static.usrfiles.com', suggesting a link farm or SEO poisoning attempt. The primary malicious URL is likely intended to redirect the user to a harmful site.

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.cc/wix?keyword=oraciones+copulativas+y+predicativas+ejercicios+resueltos+pdf
    • https://static.usrfiles.com/ugd/b7ab08_5c9d840e86d14662ab7b891bbda823cb.pdf
    • https://static.usrfiles.com/ugd/b8c837_60401a025f844128a3d0d79d7229c65a.pdf
    • https://static.usrfiles.com/ugd/fd3290_8d670cf4866a4220aaf4d5bef3b53f47.pdf
    • https://static.usrfiles.com/ugd/b8c837_f78dec1a0373414491daf7d67e769be4.pdf
    • https://cdn.shopify.com/s/files/1/0431/0722/1670/files/85296459855.pdf
    • https://cdn.shopify.com/s/files/1/0438/3319/6706/files/50697332429.pdf
    • https://cdn.shopify.com/s/files/1/0428/5664/4774/files/169149395.pdf
    • https://cdn.shopify.com/s/files/1/0433/6291/0376/files/acronis_true_image_universal_restore_iso.pdf
    • https://cdn.shopify.com/s/files/1/0433/7909/7758/files/52480336885.pdf
    • https://cdn.shopify.com/s/files/1/0431/1826/4469/files/que_es_uniforme_en_ingles.pdf
    • https://cdn.shopify.com/s/files/1/0433/1231/6584/files/diviturepexubexosixufepov.pdf
    • https://static.usrfiles.com/ugd/4b7290_47308d391b0b48cdb5d4269f73b1530e.pdf
    • https://static.usrfiles.com/ugd/97634b_a13191bb1ce04922973832c40703e419.pdf
    • https://static.usrfiles.com/ugd/e1d12c_1b1d85e4a9b6446b93d1262a675c5bd4.pdf
    • https://static.usrfiles.com/ugd/10e3af_b19f9eb2b09e4a51bf61e9604ddbc884.pdf
    • https://static.usrfiles.com/ugd/c1615c_4ed5385d50da4bd4b2e29e1d52369bdd.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_off0000623b.bin
cb59e05814fd358734dbeaf25c577370a7333c0543c3c3d3e9db4acb608e4737
pdf-font-stream PDF embedded font (sfnt) at offset 0x623B 5412 bytes
font_01_sfnt_off000074c1.bin
70514c9f0e4288f8a6bda683a94d5a8529bcc33170c3283e9776337fa70cd51e
pdf-font-stream PDF embedded font (sfnt) at offset 0x74C1 10904 bytes