Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d3cac0b2bacd99d…

MALICIOUS

PDF

37.3 KB Created: 2020-08-21 05:32:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c1511f8f0e19068041a4f3d4d5622736 SHA-1: aee126d1f51d8520d059b66e774d4f7e78362327 SHA-256: 6d3cac0b2bacd99d8157871db3ebfac408837ea1d74ae0c0a440c1289df134a5
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a heuristic firing for PDF_MALICIOUS_REDIRECTOR_LINK, indicating a link to known malicious infrastructure. The document body, though heavily obfuscated, contains a URL that appears to be a search result for 'chopin nocturnes op 9 sheet music' and also contains the malicious redirector URL. The PDF_SEO_LINK_FARM heuristic indicates the presence of numerous external links, suggesting a link farm designed to attract traffic. The ML classifier also 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=chopin+nocturnes+op+9+sheet+music
    • http://files.bromptoncourttownhomes.com/uploads/1/3/0/7/130740068/4722397fc54ff.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/5018/0503/files/future_jersey_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/2168/1315/files/debikilifu.pdf
    • https://cdn.shopify.com/s/files/1/0446/4692/4451/files/sign_language_abc.pdf
    • https://cdn.shopify.com/s/files/1/0461/9236/1622/files/53302214761.pdf
    • https://cdn.shopify.com/s/files/1/0429/6625/3724/files/52799519551.pdf
    • https://cdn.shopify.com/s/files/1/0432/9439/2485/files/nota_novel_bimasakti_menari.pdf
    • https://cdn.shopify.com/s/files/1/0433/2965/0843/files/cpc_practice_exam.pdf
    • https://cdn.shopify.com/s/files/1/0431/8950/2110/files/6418831701.pdf
    • https://cdn.shopify.com/s/files/1/0434/7081/5397/files/23139531436.pdf
    • https://cdn.shopify.com/s/files/1/0437/1401/9496/files/74824166825.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005533.bin
46e1b33053f90213beeac43a79b72b42a75ce6768e384ec6edb083d2b662ef0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x5533 4992 bytes
font_01_sfnt_off000065f7.bin
926f45082d7604d8fb14373e2003397c7bebc0c19a5c935161a117677d1e7f86
pdf-font-stream PDF embedded font (sfnt) at offset 0x65F7 10240 bytes