Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c1bdd923be7ef32…

MALICIOUS

PDF

80.0 KB Created: 2021-09-02 07:05:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7c276b6841fa910b5d4d3d7419859077 SHA-1: 1a887da84af5e5c77d64f9329ce7bf9142ac0450 SHA-256: 8c1bdd923be7ef3286ab0f944b06487e515e94b4d9caaad739b4e13d0f88be33
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm or phishing attempt. The presence of external URI heuristics and the ML classification strongly indicate malicious intent, likely to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6181

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://sl-light.ru/design/img/upload/file/ravawaju.pdf In PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/papoxi.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16116bafb3d614---gasalupenepojumavaru.pdfIn PDF document text
    • http://ambvetbrashersclavoghisu.eu/userfiles/files/visavilufuzuvirimoguvuraf.pdfIn PDF document text
    • http://www.mmalappeenranta.com/tiedostot/files/11702088260.pdfIn PDF document text
    • http://edgewood1962.com/clients/2/2b/2b25cacec04995aba37d275b9c35b4d1/File/76723665290.pdfIn PDF document text
    • http://abogarestudio.com/userfiles/file/kipogatifejabuso.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16088041a691e1---wekiziboja.pdfIn PDF document text
    • http://1982thsreunion.com/clients/a/a8/a85c6617a93da1462bf6c3e7dda9c043/File/93222517137.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a726979b761---27901204683.pdfIn PDF document text
    • https://abcoegypt.com/userfiles/files/kujezabazefomexoga.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/19b94ad22d90a94b78d5b858a86912e5/16246585185.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/24ef98118259ec8a73b78d13bf93577d/zufinuluk.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/pokurumozadesarijo.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/xitafop.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/diwenawefe.pdfIn PDF document text
    • https://zohopinler.com/calisma2/files/uploads/pafoxigine.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/wedojukepe.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e548c132ee0---11239084396.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/40728433570.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612439e0e153f---peguwolatis.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/n8g93clfigfs5ppl1n9c9c6a35/zopeve.pdfIn PDF document text
    • http://megat.pl/uploaded/fck_files/file/1001542649.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a6c4c637a---23499416993.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=how+much+weight+do+you+lose+if+you+burn+1000+caloriesPDF 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_off0000dc96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC96 11528 bytes
SHA-256: 037ce1b2417eef6cec4717063c7afc627df836ac62a00c364b446648bbb6ce09
font_01_sfnt_off0000f78f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78F 17976 bytes
SHA-256: b8f0c55bc9f87b60d25134e488a57d1add603062d9016a4db96e2923559185c6
font_02_sfnt_off000125df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1