Malicious PDF — malware analysis report

Static analysis result for SHA-256 38594e53d19e9b4c…

MALICIOUS

PDF

48.8 KB Created: 2020-03-10 10:21:28 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: c74b270139abcb7e6179435bde616157 SHA-1: efe1fb6c65730629d8b62906c684f858cf06f47d SHA-256: 38594e53d19e9b4c9bf5505233f5e9b61ab243d6e2551ba35e112d004ff2567f
94 Risk Score

Malware Insights

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

The PDF contains a large number of external links to other PDF files hosted on various domains, indicative of a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains references to URLs that are part of this link farm, suggesting the primary purpose is to direct users to these external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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 http://zhcw.brdge.org/uploads/1/3/0/9/130968979/130968979.html#define+blood+agglutination+test PDF link annotation
    • http://cuteloops.com/uploads/1/3/0/6/130620506/e78d1d3352ee.pdfIn PDF document text
    • http://littledetails.club/uploads/1/3/0/3/130323449/d1589c1176808.pdfIn PDF document text
    • http://basilicainvestors.com/uploads/1/3/0/5/130551564/717570.pdfIn PDF document text
    • http://powerbabes.net/uploads/1/3/0/5/130590383/xifurifalawak.pdfIn PDF document text
    • http://silverfoxblog.net/uploads/1/3/0/2/130272092/4d3e7e7eda.pdfIn PDF document text
    • http://adrianleeproperty.com/uploads/1/3/0/6/130621187/7949150.pdfIn PDF document text
    • http://lionheartcentury.com/uploads/1/3/0/6/130622093/tubakigivufulowotev.pdfIn PDF document text
    • http://circusbacchus.org/uploads/1/3/0/6/130604595/wevovirobuw-pilaxonizel-rovezulu.pdfIn PDF document text
    • http://www.narpestakpak.com/uploads/1/3/0/7/130739564/e6de9101e69d49.pdfIn PDF document text
    • http://www.portfolio.rachelberner.com/uploads/1/3/0/8/130873982/4673251.pdfIn PDF document text
    • http://nancymaldonado.com/uploads/1/3/0/5/130539797/selezudowuvabawolem.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007466.bin
1baebef7aa6618717ddb302d8bb8bf2d663a09e4ccccefc5827a3d2cbe0be88c
pdf-font-stream PDF embedded font (sfnt) at offset 0x7466 8104 bytes
font_01_sfnt_off00009372.bin
63f5e27ee3d24cc00d413e59c301cc73ab377383609796993547673f2bea898c
pdf-font-stream PDF embedded font (sfnt) at offset 0x9372 2600 bytes
font_02_sfnt_off00009c9e.bin
88d044d2656d2c8686ef7af8424f892f3c8652e8c0c87b0b55a4766cf2f9ba2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C9E 16576 bytes