Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ea00f51c97675fb…

MALICIOUS

PDF

88.7 KB Created: 2021-09-04 16:14:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 28390a08660e9be9426400cc84c4312c SHA-1: 63758fe24b9e5e56ca59bdc0e8421e0da0a7daa1 SHA-256: 9ea00f51c97675fb0be186712dec42f1471b7388164628f6a00540e10ee0cbb7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm pointing to compromised WordPress uploads and disposable hosting. The presence of external URIs and link farms suggests an attempt to redirect users to malicious sites, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5191

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://stroisvias.ru/userfiles/file/weburuperuz.pdf
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/edad6da9f00c6c27fb0deb6c8b70b128/27348242260.pdf
    • http://edgecs.net/documents/53976700553.pdf
    • http://jonmechina.com/ckupload/files/tawukufofov.pdf
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/d85d0653b85f6e718fbde0eea4a5fd9c/tokepamapovusoz.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160800bab17947---navudelirowedu.pdf
    • https://astefin.ro/ckfinder/userfiles/files/3261097629.pdf
    • http://szentdorottyapatika.hu/files/25337073418.pdf
    • http://bereanbaptistashton.com/clients/1/1c/1ca8668e480cca1e897b6add33210fc6/File/rejorivuxigigewevaki.pdf
    • http://kasargod.net/uploads/file/15729300637.pdf
    • http://lakes77.com/clients/47041/File/kavawob.pdf
    • https://torgradio.ru/new/files/file/95223865555.pdf
    • https://valve-toho.com/userfiles/file/41323901992.pdf
    • http://cogersquest.com/clients/f/f6/f6194b381802d71b6842d6160e8859b1/File/81589813388.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/6d39a4f79bf46bc4ee6f9a465a6f5764/21818940566.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bed90bec44---tusabipo.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a726d21f2---79511005291.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/9206aa3aff0f126d43418a15b2b47705/42485461657.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160be6c3ba620d---90646311604.pdf
    • https://eletvital.hu/uploads/files/nisetijibumezodamabudo.pdf
    • https://hasekei.jp/userfiles/file/45236866424.pdf
    • https://mallncart.com/userfiles/files/61827532137.pdf
    • http://aj-freight.com/ckfinder/userfiles/files/60922100769.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=envision+math+grade+2+teacher+edition+pdf
    • 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_off0000fe36.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE36 16792 bytes
font_01_sfnt_off0001164d.bin
995921cabb948f2c856f2b076f27044064ad6bb6f86f1d41574495da153207f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1164D 11192 bytes
font_02_sfnt_off00013024.bin
3f00e39146a8c8e6b67115252eaca3d2219e0ae2799d5ad6b280fd1ba01cfeb9
pdf-font-stream PDF embedded font (sfnt) at offset 0x13024 19596 bytes