Malicious PDF — malware analysis report

Static analysis result for SHA-256 b609b6da18e8c513…

MALICIOUS

PDF

75.4 KB Created: 2021-09-24 19:11:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6ff50c465d40d67c081dd068dc9e6682 SHA-1: b7b3bde3663c42388d393422ea870f9c5a73ee78 SHA-256: b609b6da18e8c513df6ecd2806157493a8b1d76577323eda83146e1fe06581aa
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or initiating malicious actions.

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://sangolongphuong.vn/longphuong/news/files/bisumi.pdf In PDF document text
    • https://safewatersolutions.in/ckfinder/userfiles/files/3705594099.pdfIn PDF document text
    • http://criminisiepartners.it/userfiles/files/sivafesulolozabizewu.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-14/20210914074923785764.pdfIn PDF document text
    • https://reaga.net/js/ckfinder/userfiles/files/tunagafafa.pdfIn PDF document text
    • http://naviway.su/upload/files/lurezibosuzaf.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/fagapepesobejude.pdfIn PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/suluxoligidukilarekeb.pdfIn PDF document text
    • https://camphacement.vn/upload/files/94357759273.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/56927096591.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/f49c03db4e2266a391d717432d15d4c2/xerevox.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614266cc34d10---wukupeku.pdfIn PDF document text
    • https://huanghecables.com/d/files/90425042225.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/62048069060.pdfIn PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/87418006400.pdfIn PDF document text
    • http://hanauhrova.cz/files/mitewowovakedigivafux.pdfIn PDF document text
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210917020453.pdfIn PDF document text
    • http://fuguchair.com/upfolder/e/files/20210918203255.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/viladar.pdfIn PDF document text
    • https://thisissati.com/userfiles/files/lizulubumizuvazugen.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/katutogitesozo.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613921f323eb6---gelisetefebuwuraxud.pdfIn PDF document text
    • https://tipresentoio.it/images/file/65691875747.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=ohm%27s+law+answer+keyPDF 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_off0000c075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC075 10412 bytes
SHA-256: 02ae0713a2d6d88eb4f9e8430a70daddd978819b9038757dad870549df9352bc
font_01_sfnt_off0000d801.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD801 18496 bytes
SHA-256: 630ec92b01d53e2c0f55497a116efd9c0f93b20f17c6c7cf5a3d7c3107769756
font_02_sfnt_off000107ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1