Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8541171ad50aa3f…

MALICIOUS

PDF

82.8 KB Created: 2021-09-22 15:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 707bef036510a51dcd3b9bfd080a0089 SHA-1: cbb1abcd342f11f55a8d22b0c4c486cdfbea617c SHA-256: f8541171ad50aa3fb3fef206a9d10b5e86df8b3bf0682c5b8a418c2fe8d9ec2f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links pointing to external websites, many of which are hosted on compromised WordPress installations or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://medvor.ru/uplcv?utm_term=how+update+android+10 PDF link annotation
    • http://marcobernini.it/userfiles/files/jowigajatidu.pdfIn PDF document text
    • http://thebookmarkcafe.com/uploads/files/vidozuzidure.pdfIn PDF document text
    • http://thegoshow.net/userfiles/file/88215833509.pdfIn PDF document text
    • https://plasy.com/uploads/file/7951731796.pdfIn PDF document text
    • http://gaushalango.com/uploaded_files/userfiles/files/mokinerosebitavigopep.pdfIn PDF document text
    • http://osteriailgalloelinnamorata.com/userfiles/files/94114347641.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148b5d4548b5---puparumuluvinowako.pdfIn PDF document text
    • http://aolisenjiancai.com/data/files/binexedujisipukifop.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/ridafezeruseladoxepugisem.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/42205689215.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/ee3df2a9702eb316924524a58ded068e/86532748528.pdfIn PDF document text
    • http://volvo-cars.jp/js/upload/files/65167728699.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/wilojizisu.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/12882125469.pdfIn PDF document text
    • http://studiozoppini.com/userfiles/files/59213090476.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/rufisizedigeril.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/rubiduzizebutabuselatom.pdfIn PDF document text
    • http://lamarchesainterita.be/lamarchesainterita/imgdb/news/files/dajewozivewaxot.pdfIn PDF document text
    • https://loffoxfitness.mvwebsolution.com/userfiles/files/xiwivutisamuguw.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff6b1e0185---xabenuxojemapurepobo.pdfIn PDF document text
    • http://www.bash.cl/media/file/maseretimode.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_off0000dee2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE2 17904 bytes
SHA-256: c8c3553dfdde97e844eca0a2cb79cb371286031bdf272a2d1362ac2cd3929758
font_01_sfnt_off00010d9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D9F 10524 bytes
SHA-256: dd12dbaa4bdaef23e69828ea174415a19b970165780136fb412d480bf2b8f2a0
font_02_sfnt_off000125b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1