Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1bf0ca3480359e6…

MALICIOUS

PDF

70.7 KB Created: 2021-03-31 21:04:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a8bfdc74c6dc7b8beb070094cb296699 SHA-1: 7ed682f6ff00f7df4545ea66bb52a472a19180f6 SHA-256: a1bf0ca3480359e6bb7eab57f8bf90f857a5c41ebb678e564ccf12cbf9840deb
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains a large number of external links, suggesting a link farm or redirection mechanism. The primary URL, 'https://xajibur.ru/award?keyword=borrowing+subtraction+worksheets+pdf', indicates a lure related to 'borrowing subtraction worksheets pdf'. While no scripts were explicitly extracted, the PDF structure and numerous external links strongly suggest it's designed to redirect users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://xajibur.ru/award?keyword=borrowing+subtraction+worksheets+pdf
    • https://cdn.sqhk.co/rixutixim/geigoX7/steelseries_neon_rider_ebay.pdf
    • https://cdn.sqhk.co/goberirud/jgVyE9t/27762607865.pdf
    • https://cdn.sqhk.co/wazikunal/bsjjbAs/84219026237.pdf
    • https://vobuzotoxat.weebly.com/uploads/1/3/4/7/134705481/rolakomawipigos_tufokumufo_ropowula_kuduvidul.pdf
    • https://cdn.sqhk.co/bosareke/BgiEgeO/fbi_cyber_security_newsletter.pdf
    • https://cdn.sqhk.co/suxujaba/iiyjjhf/ralefek.pdf
    • https://cdn.sqhk.co/wobagibu/hajeJhb/oceanhorn_switch_review.pdf
    • https://cdn.sqhk.co/busoleva/4YF7gcT/39356007080.pdf
    • https://cdn.sqhk.co/fewoxenovof/SifiPjc/super_karts_wildwood.pdf
    • https://cdn.sqhk.co/naludibeg/eieiev9/what_is_the_christian_calendar_based_on.pdf
    • https://cdn.sqhk.co/rivinodati/zicHiaC/17876099209.pdf
    • https://notowupoguja.weebly.com/uploads/1/3/5/3/135316513/xivorutiwufe.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/rodakarugupoko/sirepelaxuxosutuzi.pdf
    • https://s3.amazonaws.com/vibuvomomuv/how_to_resync_viper_key_fob.pdf
    • https://s3.amazonaws.com/tugumeb/bakodujupeborize.pdf
    • https://76df98a8-3e94-4eee-a6f5-23e1de06049b.filesusr.com/ugd/54c74c_47a6603ba1dc423da529f33256b702d1.pdf?index=true
    • https://s3.amazonaws.com/rizezobabub/74969055343.pdf
    • https://26577e91-18e8-42c3-8e85-49dcca1d6605.filesusr.com/ugd/195787_5501c2bca93e455eb2877e81fcc271e8.pdf?index=true
    • https://s3.amazonaws.com/zumomasugipeno/the_dark_knight_rises_script_with_joker.pdf
    • https://s3.amazonaws.com/wupixufekijax/dyson_dc28_factory_reset.pdf
    • https://s3.amazonaws.com/zabevog/1_cup_oatmeal_nutritional_information.pdf
    • https://s3.amazonaws.com/bisute/digital_transformation_market_research_report.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_off0000d680.bin
80d8509a9395e6c100327b1342a27578392dd5bf48777b02a6fe56feafa1d8fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xD680 5732 bytes
font_01_sfnt_off0000ea10.bin
27dd8208282b5c5325c7fa2382e2265850d1a1606040dc223037d83f65444660
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA10 10240 bytes