Malicious PDF — malware analysis report

Static analysis result for SHA-256 18b43f9038f03717…

MALICIOUS

PDF

117.5 KB Created: 2021-08-08 17:44:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3c8e4272449b5bff9ce0b4cfea6b16fc SHA-1: 64e632de1ee67c7f94ce8a1f744afdf97977b621 SHA-256: 18b43f9038f03717aa7960b8fcf66b6afb437bf91e3c5233be0be1fcb9f875c2
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to distribute malware. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution disguised as software downloads. No scripts were extracted, but the URL structure and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4bbd9e5fd---81352639857.pdf In PDF document text
    • http://dynamic1984.com/user_file/file/todobiboponadopokukeroko.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/79926283621.pdfIn PDF document text
    • https://carlojans.com/cms/file/69322848728.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/nalafasejesexifulekexa.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/3b3319ec43b2db054594dc02a637fe8b/26546099379.pdfIn PDF document text
    • https://fruzsiflame.hu/userfiles/file/5368168432.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf0c56273bf---mogak.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/lupivego.pdfIn PDF document text
    • http://keacg.com/upload/files/99234167325.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/8390935f50fa3e811b4e89efd5c27944/zixenoriselijixulubu.pdfIn PDF document text
    • http://mutitar.com/user_img/files/kimojefubopaladuxanebesid.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/20216585168333.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/499fc65d219074b6322fbe907407b6df/ropiruvireviduzisoto.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/8bb24d85393f3c53d91741ca7dd06f6b/xezisosuxugakolap.pdfIn PDF document text
    • http://tilestone-pools.com/i/File/95359594660.pdfIn PDF document text
    • http://eternoohydro.com/d/files/silos.pdfIn PDF document text
    • http://eprdel.cz/userfiles/file/gepal.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd70e1d012---revajuxemidamijebijomure.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608daff04f180---47608177656.pdfIn PDF document text
    • http://starke.ca/clients/84205/File/zewefarilimifigonok.pdfIn PDF document text
    • https://iwistw.com/upload/files/zozitizupizozotuxodimire.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078159837cb1---zeporifizepo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=download+sap+crystal+reports+2016+full+cracked+serial+keyPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076fc6512561---suminurej.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_off00015f1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F1C 19312 bytes
SHA-256: a9195952abee83a9dbaeccf07088bbeba5268a3482e270c953518ffe1ea3da4a
font_01_sfnt_off0001919c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1919C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001a9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A9B3 11468 bytes
SHA-256: fab8137b5e099f5084ec45e9af4ee55c1412b98ec36bc73273fa1088df01fb9c