Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c55ed80e39537df…

MALICIOUS

PDF

81.7 KB Created: 2021-09-19 04:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fef088857f5b2dc8e10bba27ef362667 SHA-1: e5f24e113b9f2a0cef05c34bec00ea74bd349f26 SHA-256: 0c55ed80e39537df54dd8a0c640a7db03c20557dd77fa94bc2379840484d8408
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and numerous external URIs, indicating an attempt to download and execute a secondary payload. The presence of a 'download button' heuristic and the ML classifier's high confidence score further support its malicious nature. The ClamAV detection as 'Pdf.Phishing.Trojan' strongly suggests a phishing or trojan distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://allytemp.ru/uplcv?utm_term=death+worm+free+mod+apk PDF link annotation
    • https://francemonde.news/UserFiles/file/nivogakasoma.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/vuxozofidujiki.pdfIn PDF document text
    • http://tomei4x4.jp/js/upload/files/kikoxokizokekefilofu.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612f354633138---zixuliwenunaripugoz.pdfIn PDF document text
    • https://eetravel.net/file/58274883771.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/wenasiminozitawepawa.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/nuwijetasoritije.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/xovubibaredagagonefoju.pdfIn PDF document text
    • https://360clothing.in/home/www360cl/public_html/uploads/images/files/rededojilubuva.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/82220445033.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/86492247864.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/pokenifexusezetu.pdfIn PDF document text
    • https://nyig.com/files/file/dokojewe.pdfIn PDF document text
    • http://mishor-uvk.com/uploads/files/87095378346.pdfIn PDF document text
    • http://milwaukee.center/userfiles/file/20458082753.pdfIn PDF document text
    • https://biholka.cz/uploades/userfiles/file/41560147655.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/161406be01c538---11064997364.pdfIn PDF document text
    • http://owop.challengersports.com/ckfinder/userfiles/files/36759571081.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/56325002835.pdfIn PDF document text
    • http://linza-market.ru/upload/files/7602094162.pdfIn PDF document text
    • http://7166867.ru/ckfinder/userfiles/files/98130508861.pdfIn PDF document text
    • https://pvesc.vn/uploaded/file/89774756473.pdfIn PDF document text
    • http://hongsung114.com/files/fckeditor/file/8249121036.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/82439651652.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
    • 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_off0000daa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B7 10532 bytes
SHA-256: 3ada436f0f5d6eec8167a76db946421aefb043d2ae57ba10a5a7bd1ba9eae638
font_02_sfnt_off00010ac6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC6 18048 bytes
SHA-256: 26b2ccdbfd690f5ceff1f74af67ae5d02adfb46f251c6a0e55f06d227aa47e7f