Malicious PDF — malware analysis report

Static analysis result for SHA-256 051070637a5fa19c…

MALICIOUS

PDF

41.1 KB Created: 2020-08-30 21:50:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7313b70bd62b009bc7a4e1954d3bc28b SHA-1: 4e1922240ff4645ae35897fdb4a13959f3653d21 SHA-256: 051070637a5fa19cefed6193b7245e7e80896bad1682622c8536c103059768bc
154 Risk Score

Malware Insights

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

The PDF contains numerous links to external resources, including a known malicious redirector. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm designed to direct users to potentially harmful sites. The document body, though malformed, contains the malicious URL, suggesting an attempt to disguise malicious activity as educational 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/wix?keyword=fun%25C3%25A7ao+quadratica+exercicios+resolvidos+passo+a+passo+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_cc77888b63c54c609c48469be275e08c.pdf
    • https://static.usrfiles.com/ugd/b8c837_cec04c638e034c9bb057eca5ea089791.pdf
    • https://static.usrfiles.com/ugd/ca300b_5adb672b43de4a819247c33198849fb5.pdf
    • https://static.usrfiles.com/ugd/9e14ca_06d2fb8b8f104b518f21e450ad8212e4.pdf
    • https://static.usrfiles.com/ugd/9e53d4_01160bb7954c489b8a57903b60cc76cd.pdf
    • https://cdn.shopify.com/s/files/1/0433/1218/5494/files/14433365239.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/51220099535.pdf
    • https://cdn.shopify.com/s/files/1/0432/0942/5056/files/5570084653.pdf
    • https://cdn.shopify.com/s/files/1/0431/3346/8821/files/39322659673.pdf
    • https://cdn.shopify.com/s/files/1/0433/6841/5400/files/90237087395.pdf
    • https://cdn.shopify.com/s/files/1/0437/7496/7965/files/65320160370.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_off00005b87.bin
d747e50381140edf9fbd4c986878a449c44708d2dc7ba885441f0d46b0a117d2
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B87 5540 bytes
font_01_sfnt_off00006e2f.bin
bb00d9131fb1178b795559b7e193af5639934881c92ccb69aa5f97dfd0402a76
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E2F 12580 bytes