Malicious PDF — malware analysis report

Static analysis result for SHA-256 11658a2bc15f56ee…

MALICIOUS

PDF

71.3 KB Created: 2021-09-25 07:44:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a3fda264602747dbf0551665c52e41e SHA-1: c44965342d564688fee4e0e88268b585c3be26e5 SHA-256: 11658a2bc15f56eed5fd9ef6f9031513cbc122708bf5ac219d0311f26ac4dff7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of link farm heuristics and compromised CMS upload links reinforces the attack pattern of directing users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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=jzkz+drastic+games
    • http://denda.co.kr/ckfinder/userfiles/files/28483812879.pdf
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614c52d9ab1d6---gijiranatiwilopodogibino.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca6e430fba---kepixopikitot.pdf
    • http://runbo.net/upfiles/files/16316919283035.pdf
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/20358352164.pdf
    • https://oxi-dental.ro/imagini_ws/62208865996.pdf
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/1ss8v1h7t56i247a2j0pd3jdv9/19017489386.pdf
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/28642923786.pdf
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/wasabevejupezu.pdf
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/u01fvdvn5ea42upuaj2f54f2l5/golugikixewid.pdf
    • https://epiphanych.com/images/file/65318055831.pdf
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/34010984189.pdf
    • http://ziva-muzika.cz/files/file/tadopediwido.pdf
    • http://metabolit.ru/files/file/40658198785.pdf
    • http://eptesteplelek.com/uploads/file/mifanipejedenu.pdf
    • https://lamaisonducoeur.ca/upload/editor/file/wubokoxokos.pdf
    • http://stin-verdon.fr/assets/Image/files/61016755912.pdf
    • http://www.ctnphrae.com/ckfinder/userfiles/files/juzedi.pdf
    • http://nakajima-ya.com/upload/save_image/files/xivozibuburomusurogaligur.pdf
    • http://bukharaatlanta.com/sites/default/files/file/xevawoxidikumidupalefi.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/68736006615.pdf
    • http://xn--dlek-5qa.com/admin/UserFiles/file/xuwivevigapetexajajakotis.pdf
    • https://yuvasarkar.org/userfiles/file/16174833256.pdf
    • https://fiscconsulting.com/userfiles/file/zojorokapesokoxa.pdf
    • https://pisausakti.com/contents/files/52935455305.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • 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_off0000b53f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB53F 16792 bytes
font_01_sfnt_off0000cd51.bin
5be8aa070cbf54c9e765a16129c2bbd7c017ab30562fdc1554d19852e7326796
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD51 16040 bytes
font_02_sfnt_off0000f5f0.bin
442e851f9d27ace85abe46a6fa814ab7a60a8e1a8324d74687e01c27aafcc5fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F0 10584 bytes