Malicious PDF — malware analysis report

Static analysis result for SHA-256 831cdc8ea5865877…

MALICIOUS

PDF

49.8 KB Created: 2020-04-04 07:51:28 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-08-25
MD5: 691b3b96106d23afb5608209247f0292 SHA-1: 24bae6ec616bce2f7239d1f00e51b2b1a85994c1 SHA-256: 831cdc8ea586587779871e9c2c524ed0ad5e2ebd6c4a4a0db0d7d32b274b418d
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the structure suggests a link farm designed to direct users to potentially malicious content or for SEO manipulation.

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://letsdanceteamnyc.com/uploads/1/3/0/4/130475938/130475938.html#hoja+de+respuestas+test+crea PDF link annotation
    • http://loveinlighthealing.com/uploads/1/3/0/8/130813055/fumosaxepuki.pdfIn PDF document text
    • http://thesailingbroker.com/uploads/1/3/0/7/130776672/22580f17e505f.pdfIn PDF document text
    • http://thebridgeconsulting.net/uploads/1/3/0/5/130546606/994716.pdfIn PDF document text
    • http://moneytreerentacar.com/uploads/1/3/0/2/130271190/c56b529c.pdfIn PDF document text
    • http://rmsinternational.ca/uploads/1/3/0/6/130640057/lapuz.pdfIn PDF document text
    • http://yamureconsulting.com/uploads/1/3/0/6/130604699/298df73.pdfIn PDF document text
    • http://spotlesspropertymgt.com/uploads/1/3/0/2/130270882/sebuwagedopineripil.pdfIn PDF document text
    • http://ellenlongmcgrawhill.com/uploads/1/3/0/6/130639926/xozabojusebuk.pdfIn PDF document text
    • http://debrios.com/uploads/1/3/1/4/131453396/nuganulem-ralixutoxodugo-bonabizexegeje-lakidenoxig.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007158.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7158 6728 bytes
SHA-256: 5278024270de67705d3a5034a26ce2f5e1d9e53f50705cc770b2190155f81e7b
font_01_sfnt_off000081fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x81FB 9248 bytes
SHA-256: 154ac7f25e835f755872385d9da630d1fc29a189cfb4408acace7f8c4fd84abb
font_02_sfnt_off0000a319.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA319 16096 bytes
SHA-256: 9955a10f44b3bbd8f8c69af80e2423d9288745809d8e230d8c4621fdf1b04c07