Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fbbcd88a073a402…

MALICIOUS

PDF

73.9 KB Created: 2021-09-11 12:38:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7bfca204b3f1a9117f1590ab238b3a2d SHA-1: 2c40e64c8f4ba2f3f1c931dd41729dd569aace91 SHA-256: 4fbbcd88a073a4021f010dacbe7963b9939ad3ab216e848a33c806c2df66055b
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous external URLs, with several hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malicious content. The presence of multiple external links suggests an attempt to direct the user to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://wastran.ru/uplcv?utm_term=android+sdk+for+intellij+idea+download PDF link annotation
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/60bae5dbb153f92dc59d27982173112f/33205041886.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/fotikulipepolenu.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/91765112164.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/25882834575.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/94542737875.pdfIn PDF document text
    • https://protraderin.com/userfiles/file/sowibanaroj.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/jivuvuwozosumarasurunu.pdfIn PDF document text
    • https://parlagame.net/calisma2/files/uploads/51129668735.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/6b928d86f34d9040a57e1e2ecfa9c4f4/juxogodisifuwakuwadilazew.pdfIn PDF document text
    • http://micdelhi.in/userfiles/file/27403204492.pdfIn PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/84096771193.pdfIn PDF document text
    • https://xn--49st2et51duvk.com/upload/files/97539988805.pdfIn PDF document text
    • http://powercleanperu.com/cms_powerclean_2015/sgi_userfiles/userfiles/files/dazidasuriridivinijev.pdfIn PDF document text
    • https://gres-k.cat/userfiles/file/lavivaxabolekuliligezow.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/8065574583.pdfIn PDF document text
    • https://attack.lt/images/files/78984792628.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/nasafutogevolanivokudew.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/f20ffc37b09f54e1a7374ce85d8cd82a/59220779121.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/nelodigakid.pdfIn PDF document text
    • https://www.gullyracing.it/admin/ckfinder/userfiles/files/lusuludez.pdfIn PDF document text
    • http://tainghe.vn/userfiles/file/dusapukuko.pdfIn PDF document text
    • http://spprp.pl/userfiles/file/73281289486.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_off0000b6fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF0F 19312 bytes
SHA-256: 7262eee79fcf43c8219ac62577113c570670b9566e18cdfe72716966f30888ad
font_02_sfnt_off0000ffec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEC 10636 bytes
SHA-256: c85f0b3c827d80e0996a538c494571c2cc0adbf165584f9acd4e6b17a42f5079