Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b9ecbb53194e6b1…

MALICIOUS

PDF

39.9 KB Created: 2020-08-18 18:47:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c60c4cadd5c9c52b2eefee0b0c6433b9 SHA-1: 749eb9d2ddbea2df3612f9572468a1803fc33825 SHA-256: 2b9ecbb53194e6b123ef07ba8add494f91bb81d3c78b5524fe3ecbfb7ba78eea
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a malicious URL, identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text related to a 'mechanical advantage worksheet' and the malicious URL itself. The PDF_SEO_LINK_FARM heuristic indicates a large number of embedded links, likely for SEO manipulation or to obscure the malicious destination. The ML classifier strongly flagged this PDF as malicious.

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/pify?keyword=mechanical+advantage+worksheet+physical+science+if8767
    • http://files.bradfordvdub.org/uploads/1/3/1/6/131606550/7388838.pdf
    • https://cdn.shopify.com/s/files/1/0428/2603/9463/files/pitebidafemigapefug.pdf
    • https://cdn.shopify.com/s/files/1/0433/4272/5275/files/fibedewiruv.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/texojorigerusoxuduk.pdf
    • https://cdn.shopify.com/s/files/1/0428/7237/3414/files/dazululegodexutewisupaz.pdf
    • https://cdn.shopify.com/s/files/1/0429/2490/0515/files/78515558388.pdf
    • https://cdn.shopify.com/s/files/1/0433/9000/9502/files/fowefezilavewezawetub.pdf
    • https://cdn.shopify.com/s/files/1/0428/3482/1287/files/fuwezexulem.pdf
    • https://cdn.shopify.com/s/files/1/0429/5196/6873/files/39455978484.pdf
    • https://cdn.shopify.com/s/files/1/0437/1064/4377/files/dubobobarebipose.pdf
    • https://cdn.shopify.com/s/files/1/0438/2933/0077/files/bootstrap_vertical_align.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004ecb.bin
b62ab50de355f11941e32d732446fc0e2be70fbed2fe21a67b3815bc3fa6c110
pdf-font-stream PDF embedded font (sfnt) at offset 0x4ECB 5956 bytes
font_01_sfnt_off0000632b.bin
72f2ad00c1a51c446873ab488aa548b01f0924fd982a1012583e454a6bddc1b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x632B 9752 bytes
font_02_sfnt_off0000848d.bin
a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
pdf-font-stream PDF embedded font (sfnt) at offset 0x848D 4324 bytes