Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef3dc0a1145e2435…

MALICIOUS

PDF

81.8 KB Created: 2021-09-16 21:54:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: d56468c43da4324eaff7b39ed1859881 SHA-1: 76ffdd8076b72bde53031b94f429aa691921e134 SHA-256: ef3dc0a1145e243540d572c69c8fe9c7d5a987f0c240e19dba8658064b40f2de
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, potentially to download malicious files or engage in phishing. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7657

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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://yousefmaktabi.com/ckfinder/userfiles/files/6144652518.pdf In PDF document text
    • http://synthecinter.com/userfiles/files/visunaguzewuben.pdfIn PDF document text
    • http://qdjshg.com/files/file/dulumibutemawelavotu.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/92697259085.pdfIn PDF document text
    • http://vin-baietii.ro/ckfinder/userfiles/files/rajemesigatadutaja.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/bojugojafabi.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/42894847867.pdfIn PDF document text
    • https://blokhol.com/upload/files/3149706123.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/d5a0n3e49vkto5buo1hpp3sljo/sigebofunisorebeki.pdfIn PDF document text
    • https://52fantasies.com/home/holly/public_html/ckfinder/userfiles/files/tosemixifibopete.pdfIn PDF document text
    • https://ferdavagnar.is/images/fck/file/bufadapuxuzigavik.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132eefe27323---jinujiberituregida.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/6677313736.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/98440807772.pdfIn PDF document text
    • http://studiogiovannone.com/userfiles/files/tagabisesepixogufu.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/vexado.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/10510743254.pdfIn PDF document text
    • http://autoscuolavalerio.it/userfiles/files/panumerefa.pdfIn PDF document text
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/38048444762.pdfIn PDF document text
    • https://agrando.cz/files/file/72332278022.pdfIn PDF document text
    • http://otczenacts.com/media/files/gatefaxiwejigofuv.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/suxatapidavoxaguvipilod.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613335c713ddf---37356634984.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/41976196465.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=apk+management+downloadPDF link annotation
    • 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_off0000e54d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE54D 19148 bytes
SHA-256: b55b8bb813923a7abbfa09f39444e0f431f0894425265fbd661a559062f399b6
font_01_sfnt_off00011605.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11605 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012e1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E1C 10532 bytes
SHA-256: 1068c0d0a82e90b89271e4423d4a8b6ac7a4c60b169e7728b59f9e28e9aae7cb