Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f6fe9c296d962b…

MALICIOUS

PDF

81.1 KB Created: 2021-07-16 05:51:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b558d7791a2b9a437a4562ac5e2271cf SHA-1: 86448b6a384045ebbcc46f6fe552fe94b596d75c SHA-256: 81f6fe9c296d962be715c06b04289a5bf88078e6350da945014a396c25237231
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised CMS uploads, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the links and the PDF structure point towards a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://irlanc.ru/uplcv?utm_term=molarity+practice+problems+answers PDF link annotation
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/62edeb779ee643fa74a82a833ef7ecef/zeritavon.pdfIn PDF document text
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/c23672a13fc5d40fe4f71710f525e44b/22066079823.pdfIn PDF document text
    • http://dorisemitchell.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rolesorofigisefapovofo.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/10656571061.pdfIn PDF document text
    • http://camionespanamericana.com/userfiles/file/modamabejelaxexirolidaf.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16087901cc4802---xifegufedire.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c83eded829---95879681786.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/1a637aee2dd830b9103a9ec116da1730/3594129445.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/3d024c3d0f3796854483d1dff8c235fc/nugajiropifidarid.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/27986775644.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080d5f508bcb---tofumulazufanofega.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160d6c4cb66e1c---donudeba.pdfIn PDF document text
    • https://zohopinler.com/calisma2/files/uploads/5749669141.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/95aa91bf4244819525945005b64a67f7/koxojibanipabeza.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16083433fc9ed4---bowunutodogodapo.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/88a6403b33d0b1942b20920858d0f220/jokusuwowifuto.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/43770839636.pdfIn PDF document text
    • http://sewakendragroup.com/userfiles/file/rugavufe.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/zerimuraxovexobo.pdfIn PDF document text
    • https://cdmsig.com/ckfinder/userfiles/files/55540922884.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c864e0e7d0---lezurugurinebube.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/bepuv.pdfIn PDF document text
    • http://seigyobannkaigaikikaku.com/ckfinder/userfiles/files/gupedomedunitamaxejumela.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160c70be12f3f3---48974374699.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/7af67a9527e5484ac6e5db8a356eb870/8675085229.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b94190c69b0---9130688879.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_off0000d920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD920 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF137 10868 bytes
SHA-256: f4c392dba63af27a4229cfdafb83ff4aec3343299cd484982b20c717c46c978e
font_02_sfnt_off00010a37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A37 17112 bytes
SHA-256: 3ed968814ba4dc3833d39b778fd14a8109e5b7d2bf23cbe6ee99e676a79ebc55