Malicious PDF — malware analysis report

Static analysis result for SHA-256 98a9b61a1d90eb26…

MALICIOUS

PDF

76.8 KB Created: 2021-09-03 23:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4baa6038b39613b909d348dce842cd07 SHA-1: 087b2689496d1496603f4e7843edfffad873d8c7 SHA-256: 98a9b61a1d90eb26e7ac6122b7df2056002bd433c740a8499a9155e530106f1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document designed to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cylinder96.ru/admin/ckfinder/userfiles/files/77293693781.pdf In PDF document text
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/ae2bdba6751d6743fad1fe10433f0208/21124443388.pdfIn PDF document text
    • https://gyn-koe70.de/obrazky/file/20782160427.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c9152a2d2---vikezonelevewal.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/16072aeaa69297---5291932035.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/gakutewijowu.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/eb15e995eb0fe7d4775efcef41ecfff7/gesefimisonig.pdfIn PDF document text
    • http://krajinar.cz/soubory/files/76736884556.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160836fc25a00a---diveka.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/17bl53uh0k9aic2tnfku8ft519/93181727438.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/66449732419.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/gihtjgnkvrnhtft6ufv0e1haij/6605329118.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/jovomifafojukupetojosi.pdfIn PDF document text
    • http://tubemakingmachine.com/uploadfile/files/wozufufegovak.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/af22283604f04aacedcc33b4cabbe590/vupejovetosurura.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/88572980636.pdfIn PDF document text
    • http://alliance-vietnam.com/upload/files/koxebetumew.pdfIn PDF document text
    • https://esperanzadeavila.com/fotos/file/75222443307.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/174421268a0f3180ff95ffaed676bf00/30971215569.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/gaktvau17ja1kv01eo2m990kj5/kofaxevel.pdfIn PDF document text
    • https://gyandeepjkss.org/userfiles/file/zirunozonajurugolivudu.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/q187bf81otr914n6kjfcogouag/9777133446.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/wugedojejokezelojuw.pdfIn PDF document text
    • http://chandigarhdatarecovery.com/files/file/vawogufifapi.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/4c9d9f1801f610ac3cb5e06b2a5d4b06/tinomob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=diet+chart+for+weight+loss+pdf+in+tamilPDF 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_off0000c817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC817 16680 bytes
SHA-256: c0d7c2c1490bc318dad6e874b6ff9d762fb53e12818f81bd300128343eebdf1c
font_01_sfnt_off0000f31b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF31B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B32 11156 bytes
SHA-256: 08dfb902c7462469ca87bd98cba940e1935e6cfeb717087f08fd3045e44f1395