Malicious PDF — malware analysis report

Static analysis result for SHA-256 5053c8b933aa5dbe…

MALICIOUS

PDF

81.6 KB Created: 2021-07-08 00:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 55e40bd86146ee410bbac13c434d90fa SHA-1: 6a9411b85b5061f535c22ffba878c5f10138e172 SHA-256: 5053c8b933aa5dbe4d18d4ac3d01c509f76b8a581de701d84196a13f83fc2f95
156 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it functions as a link farm, directing users to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were extracted, the PDF structure and URL patterns point towards an attempt to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6833

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://webcertain.net/contentupload/fckeditorUploads/organization_/file/26492000261.pdf In PDF document text
    • http://nicenpos.com/userData/board/file/dafab.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/gotugelumexuwirazi.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/98457244249.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/fejulutilazepov.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e0f263a3e---44951653351.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/14326143569.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f3ff0c79c---89583840679.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/girarevonanabizusaf.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4624e1df098a3c8e2cdda7976308248f/waduzuleloravelotewopugar.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/239247925dfbddc14ad295a8dbb75673/57913457101.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/zunimivumubajige.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca38a11aa2b---xobotezomuxes.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b17fe39edbe---86609735958.pdfIn PDF document text
    • http://cohensevents.com/clients/74638/File/ladokinenubavuvizunux.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/14091145.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077f351e1766---xenam.pdfIn PDF document text
    • http://lucann.com/Upload/file/67219172258.pdfIn PDF document text
    • http://ridendo.cz/files/file/17474785269.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/koxedinonuxigewigaroje.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/51516492949.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160aeed7825269---poninurab.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160df4500466be---88681686434.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/debodajigikonojumot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=healthy+creatinine+levelsPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/6739471f602cca8b11eaa82d126b9abf/88388768619.pdfIn PDF document text
    • 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_off0000e694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE694 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000feab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEAB 10376 bytes
SHA-256: c7f776a4cce6f349947d111b45cf89c6af4ac306c0a356fb54b8027e0bcffe3a
font_02_sfnt_off0001160c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1160C 16928 bytes
SHA-256: e7531d11838efd976079475abebdc191a3b7ca3e113426dff373d73041d33282