Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cf4757d6f574022…

MALICIOUS

PDF

37.1 KB Created: 2020-04-06 07:38:36 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-04
MD5: 8e4b0b69bb2c8dca408d6468dfca224f SHA-1: 931b36e026e8b3f7d0625a97411208ad346e6655 SHA-256: 8cf4757d6f57402202c68f4b4ea6680ff62ac36e14570a5324b3281b826c0fec
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF document contains a large number of external links, many of which are numerically or generically named PDFs hosted on various domains. The document body text, though heavily obfuscated, contains a reference to 'Brother mfc-j625dw wifi setup', suggesting a lure to trick users into clicking these links. The heuristic 'PDF_SEO_LINK_FARM' indicates a pattern of creating numerous links to potentially malicious or spam content. The primary IOC is the first external URI found, which also contains a lure related to printer setup.

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://caressofhappiness.com/uploads/1/3/0/6/130620455/130620455.html#brother+mfc-j625dw+wifi+setup PDF link annotation
    • http://50klawn.net/uploads/1/3/0/6/130604877/9846057.pdfIn PDF document text
    • http://stonefieldcottage.com/uploads/1/3/0/5/130588412/rezufusoxefatudip.pdfIn PDF document text
    • http://stefanierothert.com/uploads/1/3/0/5/130590200/zejanetu.pdfIn PDF document text
    • http://sparklyhealthandlove.com/uploads/1/3/0/3/130323454/vikaxopimuge_nimef_kalewodewiwab_padipowe.pdfIn PDF document text
    • http://canyoncitygrill.com/uploads/1/3/0/2/130289682/8224630.pdfIn PDF document text
    • http://mcbcyork.org/uploads/1/3/0/7/130739971/lununanexavulin.pdfIn PDF document text
    • http://janicehicks.com/uploads/1/3/0/7/130739061/mutipe.pdfIn PDF document text
    • http://sunniecorners.net/uploads/1/3/0/8/130874272/fikene.pdfIn PDF document text
    • http://blackfriday.dng.ie/uploads/1/3/0/7/130776152/9132682.pdfIn PDF document text
    • http://georginaamyeventcoordination.com/uploads/1/3/1/3/131379312/4180190.pdfIn PDF document text
    • http://thegiltwins.com/uploads/1/3/0/5/130589114/784726.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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000068fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x68FC 7856 bytes
SHA-256: 53c78ac86a88c345592f4a7aac52502d9f6c07e23edb17a0128c363917299040