Malicious PDF — malware analysis report

Static analysis result for SHA-256 850f24bff7bef1e9…

MALICIOUS

PDF

89.2 KB Created: 2021-07-23 08:06:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: c252d048496817ba838918955a7f11f7 SHA-1: cde14c541032144bcc9c1110be0261bce7169c8c SHA-256: 850f24bff7bef1e92e3d1a7ce63aa8616049b158b678b0ed63100f09b78a0236
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. The presence of numerous links pointing to potentially compromised CMS upload directories and disposable hosting suggests a link farm designed to obscure the ultimate destination, likely a phishing page or malware download. ClamAV detection and ML classification strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://genegurumiraclehealer.comuserfiles/file/11173982631.pdf In PDF document text
    • http://daotaonhaccong.com/uploads/userfiles/file/93325026048.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/393c6797d258d3599dba999dbe3fab72/rarurutur.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160859dfae3eb7---94015055776.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc4ca6b8ec---15829702077.pdfIn PDF document text
    • http://stembridgefamilyreunion.com/clients/0/0d/0db03be1a97f3028174cafb645c8c91f/File/31656581276.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c25a38ca06f---zarosafupebak.pdfIn PDF document text
    • http://apvn.info/userfiles/file/80375323748.pdfIn PDF document text
    • http://kalikraft.com/images/file/xegule.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/57274680031.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/02d3d069a98b9e344d2ed42b6550efe3/19144876325.pdfIn PDF document text
    • https://clubforeducation.com/FCKeditor/userfiles/file/rolukawikejiragofejifekif.pdfIn PDF document text
    • http://a-mega.ua/images/uploads/file/96103626512.pdfIn PDF document text
    • http://bakoca.hu/files/file/76681435182.pdfIn PDF document text
    • http://casaalu.com/luutru/files/meduzukubevamilepazebe.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/33879364673.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/gosulokolejozowupu.pdfIn PDF document text
    • http://maduraicaterers.com/app/webroot/js/ckfinder/userfiles/files/segubexakobigogitipekepob.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160916720a886b---77738915019.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/64564986462.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc10c3bcbb---pafaxij.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607a30af9c96f---kibudis.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16071bfaad379e---kakunidoge.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=names+that+start+with+an+s+for+a+girlPDF link annotation
    • 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_off0000f93d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF93D 17260 bytes
SHA-256: 7f8251cd1c026705c8e22ad7445376412078dba94162fb454b6e6b362f680428
font_01_sfnt_off0001265a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013e71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E71 10724 bytes
SHA-256: 310c756286522d9e170be2f94097097b9d272c4899c683786e1a06006966cb2d