Malicious PDF — malware analysis report

Static analysis result for SHA-256 f35b00bd389eaa6e…

MALICIOUS

PDF

47.7 KB Created: 2020-09-19 09:57:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cd8e6c608bb55ce22d9f398c727ced9e SHA-1: f9fea5657396b5de99d475ee8d7cf270051d53ee SHA-256: f35b00bd389eaa6eef5a8f0e89960a03c8fa72d1224641daaafb5a932bddcd75
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a significant number of embedded links pointing to various PDF documents, indicating a link farm. One critical heuristic identified a link to known malicious redirector infrastructure. The ML classifier also strongly flagged this PDF as malicious. The embedded document body text is largely unreadable but contains a URL that aligns with the observed malicious redirector.

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=worksheet+%25237+commissions+answer+key
    • http://zalepo.alabamatransportation.org/uploads/1/3/1/3/131381787/dowexu-sawekizaser.pdf
    • http://files.thestandardcanvas.com/uploads/1/3/0/9/130969808/kavuvopawunedag_daxuzute_rilelenile.pdf
    • http://files.midwestdressage.org/uploads/1/3/1/4/131453867/dilibarofaxi_bazemunoruw.pdf
    • https://55f8172b-09b5-47c8-9949-e9384cbe7aa3.filesusr.com/ugd/ce4b7c_e0d64b7c1178435aab3245ba92ac3706.pdf?index=true
    • https://cdn.shopify.com/s/files/1/0429/9191/1066/files/complete_pet_student_s_book_vk.pdf
    • https://cdn.shopify.com/s/files/1/0433/3161/6923/files/bazekusuwir.pdf
    • https://cdn.shopify.com/s/files/1/0428/1440/6823/files/41878544838.pdf
    • https://9bf403e5-59ab-4bd9-86b3-df1fbea23858.filesusr.com/ugd/e7e4a0_9c292ff9219f412a9395c0692d324970.pdf?index=true
    • https://f7c32336-9183-4774-ad62-d59c6dfb1c56.filesusr.com/ugd/e6e573_c96ca6d71f3242f09b769a86e3f8e275.pdf?index=true
    • https://e9f98cce-9315-403b-b8fd-f314b1f7c402.filesusr.com/ugd/cc15ef_7effc89d2f0640889a608d05ff4e66c1.pdf?index=true
    • https://03916d10-1e80-4ef7-ab59-d0693fe75f39.filesusr.com/ugd/c1de29_33f8664d9a374e87bff5311ca7399d88.pdf?index=true
    • https://d5032517-af5d-4905-9d99-677929b395bf.filesusr.com/ugd/868401_7db44f503955458fb111f14cd98c7374.pdf?index=true
    • 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_off000078fb.bin
912de047f9d944948e14f56c8d2131f26ecc8b9b94e75b7736575df8676d2a94
pdf-font-stream PDF embedded font (sfnt) at offset 0x78FB 4600 bytes
font_01_sfnt_off000088a2.bin
992495f03ab66cacd7ec1e28effcba2f5d59ed43b09b1e94f53fe2b37f301ba1
pdf-font-stream PDF embedded font (sfnt) at offset 0x88A2 12792 bytes