Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb5a58097315de95…

MALICIOUS

PDF

47.9 KB Created: 2020-04-03 14:58:14 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: f21cf5ff38fb71566f65073da67f888a SHA-1: 8d0d74f13f3dab3b0ef2ac576b70bbeec2a0caf2 SHA-256: cb5a58097315de950b8c90b913be8af97d6c93d302143df0888e4b813dcd915c
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link T1059.001 PowerShell

The PDF contains a large number of external links, many pointing to domains that appear to be part of a link farm designed for SEO manipulation. The document body, though heavily obfuscated, contains references to educational material and the PDF's creation tool, suggesting a lure to disguise the malicious intent. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs reinforces this assessment. The primary attack pattern involves redirecting users to potentially malicious content hosted on these external sites.

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://rusticarrowofnc.com/uploads/1/3/1/3/131398204/131398204.html#ejercicios+matematicos+segundo+grado+primaria
    • http://teamshatters.com/uploads/1/3/0/6/130621464/betotuwute.pdf
    • http://olaskarinjournalismpiecesprofile.com/uploads/1/3/0/8/130813461/jumigugikozu-zekimavorut-defigiluno-baduzev.pdf
    • http://americasisraelone.com/uploads/1/3/0/5/130588822/votukerakiko-vubivi.pdf
    • http://milkywayfarm.net/uploads/1/3/0/2/130287930/2ef79c.pdf
    • http://teamturbosportsmanagement.com/uploads/1/3/1/4/131408224/segasolopakikavube.pdf
    • http://lcpm.online/uploads/1/3/0/7/130738506/9370511.pdf
    • http://spring2consulting.com/uploads/1/3/0/6/130603832/2209872.pdf
    • http://iphonephotoclub.com/uploads/1/3/1/3/131381602/dejumekog.pdf
    • http://helentwomey.net/uploads/1/3/0/7/130775448/e59ead9008.pdf
    • http://kathrynfa.com/uploads/1/3/1/3/131380495/806006.pdf
    • http://mateobaygualnespattiphotography.com/uploads/1/3/0/7/130775998/bojukule.pdf
    • http://wordsoftheheart.ca/uploads/1/3/0/5/130542936/3927124.pdf
    • http://establishingyoursteps.com/uploads/1/3/1/4/131409574/543790.pdf
    • http://3eatonpines.com/uploads/1/3/0/6/130604358/9855816.pdf
    • http://toonbearxb.com/uploads/1/3/0/4/130488175/nikiki_boniwasowu_wizibiwov.pdf
    • http://propertyinvestmentworld.org/uploads/1/3/0/6/130639246/b70f3ee381.pdf
    • http://ministryiq.net/uploads/1/3/1/0/131071041/ac572bdb10a8d9.pdf
    • http://cleanrentals.app/uploads/1/3/0/6/130640110/kepokuni.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/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009025.bin
1067921633d3f7c569baa6319dbbff53735891996b87d42affba2bdd4f92ae28
pdf-font-stream PDF embedded font (sfnt) at offset 0x9025 8888 bytes