Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c1834c532a3866c…

MALICIOUS

PDF

61.2 KB Created: 2021-09-04 01:14:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c38ea6905dd40eb53f1633757889359c SHA-1: 806054d1997af27c8094473f454ef1bfd75f5889 SHA-256: 4c1834c532a3866ce08218e1d4a7a05babd4a3f23aaa1bb94d8d3a395f46c479
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites used for file hosting. This suggests the PDF is designed to lure users to these compromised sites, likely for phishing or to download further malicious payloads. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6429

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16115a73cd117b---fosug.pdf In PDF document text
    • https://armagedonspedycja.pl/files/file/91703591409.pdfIn PDF document text
    • http://ambartakip.net/belgeler/file/nuliworijazevopepitev.pdfIn PDF document text
    • http://bassbasement.org/userfiles/file/40139205616.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb31ad5c11---fagovujojol.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160fce163827a1---fegebosul.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/94ba7c1e393cda7f994a797759ddcf7f/dojuzufijoxawu.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/4a894de775dff15455762f37e24aba7c/farusefiruwatiki.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/zudejoreligojoxixurox.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/34067822518.pdfIn PDF document text
    • https://lotteppta.net/beta/assets/file/70078764576.pdfIn PDF document text
    • https://triangle-electronics.com/assets/userfiles/file/vojofemedoruwixevenuzokeb.pdfIn PDF document text
    • http://khacdautron.com/Images_upload/files/39921091854.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be77ba4b545---52793199664.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/9bcb93f3d0294a4c139e24b70be6671f/1809400451.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f58f8e6dc---vedabimanezuxosorejer.pdfIn PDF document text
    • http://sshs61.com/clients/6/60/60e739d5a8cf4a6710e4f064fd99417d/File/32843263532.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/23339694987.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/debesutivugatupibaj.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd6b823d42---pojizag.pdfIn PDF document text
    • https://tempegaring.com/contents//files/mebojiputopapo.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f54f248719---13686047034.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/jakokusixuwexelegajumu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=calibre+pdf+font+sizePDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1D3 11692 bytes
SHA-256: a5f6b56b19e6207583557e0442cc4edc28a5136b9f50d23389842ded15d360e2
font_01_sfnt_off0000ccd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCD2 14020 bytes
SHA-256: 41087f84b00bcc27b76adb8f493d2c4ae7e413ec9eab27e2fb38220853fc4a83