Malicious PDF — malware analysis report

Static analysis result for SHA-256 bfb9c78b080d826d…

MALICIOUS

PDF

38.8 KB Created: 2020-08-22 22:23:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c689942ba08378b74a13b464884cdf9f SHA-1: 7efbb8718ee3674834531035177417ee4f4c6b3b SHA-256: bfb9c78b080d826dba4b2750342d8636bbd1edd5e41a50d22872ad2e3b09ab8f
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL 'https://ttraff.ru/pify?keyword=boutonniere+deformity+toes', which is flagged as malicious. The ML classifier also strongly indicated maliciousness. The primary attack vector appears to be a link farm designed to redirect users to harmful sites.

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=boutonniere+deformity+toes
    • http://files.hurjungeun.com/uploads/1/3/1/3/131382330/269a005f0d.pdf
    • http://files.drgigisrmuf.org/uploads/1/3/1/8/131858916/tetajop_boxiborefevoxo.pdf
    • http://files.alpujarra-granada.com/uploads/1/3/0/8/130874295/sidisivujid.pdf
    • http://files.edgerealtyph.com/uploads/1/3/2/6/132683142/9437373.pdf
    • http://nisab.fernandoandradeart.com/uploads/1/3/0/8/130874247/2509671.pdf
    • https://cdn.shopify.com/s/files/1/0434/5010/6018/files/16302229170.pdf
    • https://cdn.shopify.com/s/files/1/0432/5959/2864/files/bmw_3_series_owners_manual.pdf
    • https://cdn.shopify.com/s/files/1/0433/7005/3782/files/ninazizuxi.pdf
    • https://cdn.shopify.com/s/files/1/0433/9741/5077/files/20277681164.pdf
    • https://cdn.shopify.com/s/files/1/0432/0870/4164/files/fusion_360_software.pdf
    • https://cdn.shopify.com/s/files/1/0437/8879/6065/files/48469221774.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/78046530146.pdf
    • https://cdn.shopify.com/s/files/1/0432/8233/3864/files/zumakufudajixukoditij.pdf
    • https://cdn.shopify.com/s/files/1/0432/0552/5661/files/godazubolekil.pdf
    • https://cdn.shopify.com/s/files/1/0427/5827/5238/files/48464213011.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_off00005d04.bin
6fa8e8617feca78bd4960a8fdf774d17c9e66d4f5fd25b2735428769da6d5534
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D04 4964 bytes
font_01_sfnt_off00006ddb.bin
2fe484bd77aec2ec03931bd595be6f676530b4c92eea09f111dc53e4307a3bde
pdf-font-stream PDF embedded font (sfnt) at offset 0x6DDB 9600 bytes