Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca8f137956fb3e21…

MALICIOUS

PDF

80.1 KB Created: 2021-06-25 12:02:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff8a27cd03a286ff751ad8b855dc0b52 SHA-1: bc4607a3f6d796125f7389b10e623d283dd04261 SHA-256: ca8f137956fb3e216c8c730f91dc25fa160cd547524b9265474afb205334f1e7
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm and a lure to install a browser extension or update, which is a common social-engineering tactic for malware delivery. The embedded URLs suggest the document is designed to redirect users to download potentially harmful files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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://krisoc.ru/uplcv?utm_term=all+apk+app
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7e1181387---7204059890.pdf
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607801580234e---judumogejipuk.pdf
    • https://soechi.id/userfiles/file/sobamijosuruvisaxo.pdf
    • https://driftwoodcc.com/userfiles/files/fazip.pdf
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fffa21175b---16889981633.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160b425bbca978---dafajolisigajakedu.pdf
    • http://aggengr.com/uploads/CMS/file/jurubixexelizaxozisupuze.pdf
    • https://atcotourismtravel.com/userfiles/file/bepitipalovidax.pdf
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/2ec3021c225b51d5f74b9f01e5b2e4f6/jidofidupiletewove.pdf
    • http://matstravel.ru/userfiles/file/zetubatunazoledirukogi.pdf
    • https://pmeds.us/userfiles/file/botajodemil.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a45c0c118e7---fodumumokobapapibodulori.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160795adb925d9---pelozedusivatuwefe.pdf
    • http://m2mus.ca/clients/b/b1/b1ca46fdb12d68e762e4a8b3318caec0/File/47568275495.pdf
    • http://laweasy.kr/userfiles/file/vamedepavirefeketazina.pdf
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/3481261b63acf7fa57ccdb2d223ff9a8/20549147000.pdf
    • http://kelvista.lt/images/files/14174447975.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/b2e9c28808d71c0bdae0055410fb31b2/861411185.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ba17675c233---jegopubuveduxel.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d871.bin
d5a19663329b91fe69ef5c3562fe067656fb7aaaf9d5a569d34c02c0d83ff636
pdf-font-stream PDF embedded font (sfnt) at offset 0xD871 17888 bytes
font_01_sfnt_off0001075f.bin
a4fba55ab608a127e2af8959519c134ce9b112f0cef13c887ccedc602258d3d2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1075F 9504 bytes
font_02_sfnt_off00011bdf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDF 16792 bytes