Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9b8ce171942e68…

MALICIOUS

PDF

81.6 KB Created: 2021-09-01 17:48:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6ef6ccdcfb96a9a07f179ac544296bda SHA-1: 1a5acbce951e2ff3d0773d59832737cdcebbae76 SHA-256: 4c9b8ce171942e68d4cf162dfd2e43d97b6ec7a82bd480eca2877d8ea7f02b6e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded JavaScript, though not fully analyzed here, likely contributes to the malicious functionality by facilitating the redirection or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://medvor.ru/uplcv?utm_term=square+root+of+1800 PDF link annotation
    • http://xn--sanitrprofi-p8a.ch/fckeditor/editor/images/file/22519674305.pdfIn PDF document text
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/d36c770c589bfae5e782143f91bffa00/pesugoxozakojapuki.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b08ebc4ec48---98289655533.pdfIn PDF document text
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2b40b93a1---vopivobovofotuj.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf9f381725---kojawomiresofe.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/cc4f79da4175f073fd61a6ab426442ca/50266388331.pdfIn PDF document text
    • http://nhs1968.com/clients/65482/File/39845938469.pdfIn PDF document text
    • https://www.andreivieru.com/ckfinder/userfiles/files/gexiba.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160e372ca488ba---43256411947.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/hvtci5gn0pt9tug94riegr0t53/18091799911.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/djo9eg6tun4apnfuulacdqmerj/19290999019.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/2689248557.pdfIn PDF document text
    • https://interface-graphique.com/upload/editor/file/262405307.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/b86590f74f821df4b5d3def7263ad510/97912189142.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/42580763548.pdfIn PDF document text
    • https://bnovum.hu/downloads/15801153978.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/94314666703.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/danirawofi.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607438a35eba1---lovatanudu.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/hbd90m8u8bdv09lvhalpa4s9k8/31193122401.pdfIn PDF document text
    • https://tvsporedi.si/vsebina/dixiliwixavadoliganagu.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/wepizefazunijik.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/koxosexexixusixik.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160772707c8b7c---widajidijuguxivusose.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16114e5fa95920---62238414969.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_off0000d7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF005 18572 bytes
SHA-256: ade3d803568f39eac07ff70507c7b51b0548b188f985e64f062d551064012fe5
font_02_sfnt_off00011ff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF0 10500 bytes
SHA-256: 66ea87cacffb76bade0519d4b9251fca38097c0a3dd9f49c356be68c4f1ae7bb

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