Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b9296c9c117625…

MALICIOUS

PDF

54.1 KB Created: 2020-08-30 21:31:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e82f52a807252252a42acb78cebaead6 SHA-1: 701e0a00b0454509b503e1a95287332670bff612 SHA-256: 85b9296c9c117625ad13e2b5df1488dacfa59a74e412e26b14452b780e15e2c9
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many pointing to external PDF files, which is indicative of SEO poisoning or a link farm used to distribute malicious content. One of the primary links, 'https://ttraff.ru/wix?keyword=boredom+form+a+sentence', is flagged as a known malicious redirector. 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.ru/wix?keyword=boredom+form+a+sentence
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_a5df11c53f3d4faba3d9b4c8ef134d20.pdf
    • https://static.usrfiles.com/ugd/b8c837_71122891b4c64d9488dcbdef0f8eca2c.pdf
    • https://static.usrfiles.com/ugd/b8c837_8d49e5c5caf9482085299ed73482cb7e.pdf
    • https://static.usrfiles.com/ugd/b8c837_0598930035914fd496030eb455129688.pdf
    • https://cdn.shopify.com/s/files/1/0435/8812/4830/files/chess_game_free_for_android_apk.pdf
    • https://cdn.shopify.com/s/files/1/0432/5556/2398/files/50955366378.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/62374455636.pdf
    • https://cdn.shopify.com/s/files/1/0428/5893/8531/files/85308531510.pdf
    • https://static.usrfiles.com/ugd/b8c837_f3fe03b5f37441ef8720a6ec74cb2d99.pdf
    • https://static.usrfiles.com/ugd/b8c837_ab1ce2e910374072bfb857a175e262b6.pdf
    • https://static.usrfiles.com/ugd/b65acf_d94e517d0aa74a8684eb661016999e51.pdf
    • https://static.usrfiles.com/ugd/299074_652524c351a14a3bbb9726350c54df14.pdf
    • https://static.usrfiles.com/ugd/d9d1f5_ea03b5fcea214c8b9ad3d1bd244200dd.pdf
    • https://static.usrfiles.com/ugd/b8c837_eab1f5ba57d3473eb3ce059b61ccb77c.pdf
    • https://static.usrfiles.com/ugd/b8c837_fd6c8e0a3cb7448b9d2ccae6fdfe30c9.pdf
    • https://static.usrfiles.com/ugd/74a852_35b2004bfea34ade9294f86f5ecbf31c.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009868.bin
357f76542048c29a1612bebe1de73a2506457b60bef23e30d5af92aa48fbc5c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x9868 5184 bytes
font_01_sfnt_off0000a9f0.bin
f14740a027621a7dd370479884adb923aaa961ce92c24a591df28b956cc5862d
pdf-font-stream PDF embedded font (sfnt) at offset 0xA9F0 9856 bytes