Malicious PDF — malware analysis report

Static analysis result for SHA-256 5961a9ca48ef7e05…

MALICIOUS

PDF

33.1 KB Created: 2020-08-23 20:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0de4e0e9d890b08717542de86830220a SHA-1: c12efe41336fdf03c1fad6f965a226fc8c94d013 SHA-256: 5961a9ca48ef7e05812872b8c185b673f98f7bbc21906ec20a099db05417a68b
152 Risk Score

Malware Insights

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

The PDF file was flagged by multiple critical heuristics for containing a malicious redirector link and a large number of external PDF links, indicative of a link farm. The primary malicious URL identified is https://ttraff.ru/pify?keyword=homographs+worksheets+grade+2, which is known to redirect to malicious infrastructure. The document body, though heavily obfuscated, also contains this URL and numerous other PDF links hosted on domains like cdn.shopify.com and files.achapeyama.com, suggesting a coordinated effort to distribute or link to potentially harmful content.

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=homographs+worksheets+grade+2
    • http://files.achapeyama.com/uploads/1/3/1/3/131398452/kafetanarig_siluwopa_teguv_dosanonujulur.pdf
    • http://files.smsband.org/uploads/1/3/2/6/132695492/8846537.pdf
    • https://cdn.shopify.com/s/files/1/0431/6109/2250/files/rexelajifilebusif.pdf
    • https://cdn.shopify.com/s/files/1/0433/4950/8250/files/jabezuv.pdf
    • https://cdn.shopify.com/s/files/1/0430/8451/3444/files/44588991213.pdf
    • https://cdn.shopify.com/s/files/1/0431/9356/5342/files/capraria_biflora.pdf
    • https://cdn.shopify.com/s/files/1/0433/4570/7166/files/65257964772.pdf
    • https://cdn.shopify.com/s/files/1/0435/5332/5224/files/nixidovexerezumetov.pdf
    • https://cdn.shopify.com/s/files/1/0435/6567/8755/files/nimop.pdf
    • https://cdn.shopify.com/s/files/1/0430/9850/5377/files/97075917123.pdf
    • https://cdn.shopify.com/s/files/1/0429/0134/0319/files/61140148381.pdf
    • https://cdn.shopify.com/s/files/1/0436/9648/8613/files/diridesodasewuketiseg.pdf
    • https://cdn.shopify.com/s/files/1/0430/5482/5621/files/formulas_in_chemistry.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_off0000418a.bin
a15e1b7c0e1fa70ecd4bff4abf9f197e69cf69fc291c180941675e8a00a80c4d
pdf-font-stream PDF embedded font (sfnt) at offset 0x418A 5588 bytes
font_01_sfnt_off00005476.bin
5b8a237402a6947c2ca3cbd1136f3f01fe8b9e032a20d5fb61c92ed951a604f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x5476 9780 bytes