Malicious PDF — malware analysis report

Static analysis result for SHA-256 b41005a3ff5bdb02…

MALICIOUS

PDF

40.1 KB Created: 2020-09-11 20:15:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ee3623568ee5abe3abb91ca2d8de6c12 SHA-1: 5db8bf62ea9c92bcfbf9abcb144ae5c2d8f4b9f7 SHA-256: b41005a3ff5bdb02ab6f427618c94bd564c3c2784e22a7f68cc1172446888637
152 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, including a direct link to a known malicious redirector and numerous links to a PDF link farm. The document body, though heavily obfuscated, contains text related to 'Oasis academy brislington school uniform' and the wkhtmltopdf tool, suggesting a lure to disguise the malicious intent. The ML classifier also strongly indicated maliciousness.

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.me/wix?keyword=oasis+academy+brislington+school+uniform
    • http://kokelofe.gainstageproductions.com/uploads/1/3/0/8/130874207/6587604.pdf
    • http://files.neora.ca/uploads/1/3/0/7/130739769/c62a14b220f0d69.pdf
    • http://files.rollinsmovingservices.com/uploads/1/3/1/3/131384070/mafavipilironugoguge.pdf
    • https://cdn.shopify.com/s/files/1/0435/0020/8294/files/apa_bibliography_page_format.pdf
    • https://cdn.shopify.com/s/files/1/0439/4362/4872/files/blichmann_fermenator_manual.pdf
    • https://cdn.shopify.com/s/files/1/0434/4024/2840/files/medical_certificate_format_for_college_admission.pdf
    • https://cdn.shopify.com/s/files/1/0459/2258/2679/files/44339567327.pdf
    • https://cdn.shopify.com/s/files/1/0433/3089/6026/files/46320977481.pdf
    • https://static.usrfiles.com/ugd/fbccce_460bb03de89246b8950906e4b916a20b.pdf
    • https://static.usrfiles.com/ugd/99965f_5bfb3900a4984c7baf77f57ce1d3a9dc.pdf
    • https://static.usrfiles.com/ugd/ab059d_412e30e2612f47609ca0adb2a14f5a58.pdf
    • https://static.usrfiles.com/ugd/a891c0_5514d3c3d2dd4685a32dc066900adb4d.pdf
    • https://static.usrfiles.com/ugd/4479ed_df500d2fa5f74af4bb8d58d54c368ad9.pdf
    • https://static.usrfiles.com/ugd/70c1f8_5d35349a8c0946b8b33c125b6e538352.pdf
    • https://static.usrfiles.com/ugd/3aee12_0f5287867dc446dc8eec9aa646568dde.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_off00005ec1.bin
eb2b3b968a27eb2cf55fcf6d52efd6bc1132bc8efd4ffa00e2a6da60dbc44d7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EC1 5704 bytes
font_01_sfnt_off000071fa.bin
9751c149ad4da4d53b0f82b103ba8b15f264927309f3e1b50b46ecd8f286e60b
pdf-font-stream PDF embedded font (sfnt) at offset 0x71FA 9808 bytes