Malicious PDF — malware analysis report

Static analysis result for SHA-256 591e63c4a84a0292…

MALICIOUS

PDF

80.3 KB Created: 2021-09-22 14:08:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7b2f1d88f689d97be9e0a9458f658b94 SHA-1: fe83a42648e2ca4c129d5ac3ee2b72a9cc1f0cf6 SHA-256: 591e63c4a84a02921e96153c41e51c6b7c746a5723bb412c15b3561c9a5b5a7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of 'utm_term' parameters in some URLs further supports a phishing or scam-related lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://crewmak.ru/uplcv?utm_term=phone+emulator+app PDF link annotation
    • https://bayihoki99.com/contents/files/48161352217.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/86135902798.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/58251686980.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/30778077399.pdfIn PDF document text
    • http://moiarchitekci.pl/pliki/file/4914427328.pdfIn PDF document text
    • https://havilahbuilders.com/userfiles/file/78424761540.pdfIn PDF document text
    • http://aexpress.lv/index/images/up/file/45274700681.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/sokoto.pdfIn PDF document text
    • http://prepearl.com/uploadsfile/35484722089.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161346020d0c80---jipuxadeke.pdfIn PDF document text
    • https://familienbilstrup.dk/ckfinder/userfiles/files/75230945668.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/5d108adcebc7efdccdde9e17d1fd6043/rajunawo.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/09/02/gomurubatikenog.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/13458777384.pdfIn PDF document text
    • http://www.premiumimport.nl/ckfinder/userfiles/files/79825683991.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/73145c405c4d55d28f63334b22e80c39/54431953156.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/runamirexowuti.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/a7g2gj2mu16ra3cp97e4v3jp81/tezoronotukidiwatase.pdfIn PDF document text
    • https://crownprolaw.com/userfiles/Proj_Name/files/82921547290.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/safufafemamin.pdfIn PDF document text
    • http://xaydunglenguyen.vn/upload/files/884cea.pdfIn PDF document text
    • http://locum-system.pl/userfiles/file/19091633389.pdfIn PDF document text
    • https://fu-ko-property-agency.com/webroot/editor-uploads/files/pebexarela.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In 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_off0000d7d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE4 17220 bytes
SHA-256: 9e373b3d5611196d4ddbc58a6b2559e10d5bcd5d5cdb055a17867174bbcec718
font_02_sfnt_off00011ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA1 10360 bytes
SHA-256: 859affe8baa304913e2a3fb0c72e0d4615f6f2f628b8e5f4961208c952fd795d