Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8169785f406cb15…

MALICIOUS

PDF

47.7 KB Created: 2020-08-11 09:18:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cfde2e1ab4691b53210c5f3705fabb60 SHA-1: 2838f4eb67ebec552b0a18c48fae36184f4af2bb SHA-256: d8169785f406cb156a7abe48f0e243d9c9df03c411361f0f4b9a9840f61d31fe
152 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, many of which point to external PDF documents hosted on various domains, including a known malicious redirector. The ML classifier strongly indicated maliciousness, and the presence of a redirector URL suggests an attempt to lure users to malicious infrastructure. The document body itself is heavily obfuscated and contains the malicious redirector URL.

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/pify?keyword=antigen+and+antibody+pdf
    • http://files.cilentoreview.com/uploads/1/3/0/8/130814717/45beb8dfa7c9b.pdf
    • http://files.keyinmigration.com.au/uploads/1/3/2/6/132695513/senoxipa-vilegevujiko-kopofew-kepanigile.pdf
    • http://files.learningforlittlepeoplepreschool.com/uploads/1/3/1/4/131453950/92198.pdf
    • http://files.barrvillemc.org/uploads/1/3/0/7/130776118/423244.pdf
    • https://cdn.shopify.com/s/files/1/0435/5883/0229/files/bacterial_pathogenesis_salyers.pdf
    • https://cdn.shopify.com/s/files/1/0428/1162/1543/files/kamagulizipitatidabe.pdf
    • https://cdn.shopify.com/s/files/1/0431/4382/3517/files/13636461017.pdf
    • https://cdn.shopify.com/s/files/1/0432/4347/1003/files/20132428028.pdf
    • https://cdn.shopify.com/s/files/1/0431/7554/2950/files/death_knight_5e_bestiary.pdf
    • https://cdn.shopify.com/s/files/1/0437/6068/1109/files/logitech_trackball_driver.pdf
    • https://cdn.shopify.com/s/files/1/0431/4651/0504/files/59482918362.pdf
    • https://cdn.shopify.com/s/files/1/0433/9433/4869/files/petomifamizadijogepovevip.pdf
    • https://cdn.shopify.com/s/files/1/0429/3391/1705/files/gumakodisitob.pdf
    • https://cdn.shopify.com/s/files/1/0430/8326/8263/files/85325570671.pdf
    • https://cdn.shopify.com/s/files/1/0434/6917/6985/files/angeles_y_demonios_libro_google_drive.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_off00007d7f.bin
9a58d770bbda1d2ab47912420923b71c8def501433dbff66a1ea6d9ec72c8874
pdf-font-stream PDF embedded font (sfnt) at offset 0x7D7F 5132 bytes
font_01_sfnt_off00008f0e.bin
b38209764e86530e9d3459447b04023674d18fc2502e2931756b3068f8ae8d59
pdf-font-stream PDF embedded font (sfnt) at offset 0x8F0E 10104 bytes