Malicious PDF — malware analysis report

Static analysis result for SHA-256 4941458f8b9d6e03…

MALICIOUS

PDF

83.4 KB Created: 2021-09-20 19:02:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1c4ab4a597e7cc2c1e01f318bdfadcf1 SHA-1: 58d3bcd0abd54bc95b41005ddc8e7d695768fa0c SHA-256: 4941458f8b9d6e036b9c6da6de75c3da8cae4913ccb25049d010ca3aab7814f0
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content or phishing pages. The presence of external URIs and compromised CMS upload links indicates a likely attempt to distribute malware or facilitate phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://oniceh.ru/uplcv?utm_term=android+view+text+messages+on+computer PDF link annotation
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161396368580d2---musizowevobabesuxa.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/ebohkpj3fig2go089lavdb6c12/robiboxe.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/kd2teu4hnrf6p18hmcfvm52atj/dorevunikaxitadedefesevu.pdfIn PDF document text
    • https://inprovitperu.com/ckfinder/userfiles/files/xujamujevejetezowokane.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/63924942487.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/3453aff1aa80c57e9d81d343a4671730/tewuvukuduse.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613181f0180c4---fetug.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/27138145840.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/161533089933.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/85536860671.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/katinawugipepideju.pdfIn PDF document text
    • https://limadelimon.com/images/file/13689722607.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/sedegajosob.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/negadikudot.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/samofepaj.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/gopeboxuf.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/gimunomijepavaxeruzabu.pdfIn PDF document text
    • https://travelone.ae/userfiles/files/derukufiroxodunar.pdfIn PDF document text
    • http://chatfieldfarms101.com/userimages/funet.pdfIn PDF document text
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/76105358397.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161480f6c2dfd2---41208874352.pdfIn PDF document text
    • http://www.johnrealestate.in/ckeditor-ckfinder-integration/uploads/files/tativ.pdfIn PDF document text
    • http://kbinteriery.cz/userfiles/file/38049700697.pdfIn PDF document text
    • http://xn----otbbfbbknchz.xn--p1ai/sadm_files/vumegatibipasubibukovud.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/walosijumaburujaw.pdfIn PDF document text
    • http://brenno-tojestto.pl/userfiles/file/11422308967.pdfIn PDF document text
    • https://migger.dk/userimages/file/37409324112.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_off0000dbf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF2 18928 bytes
SHA-256: d2403d83de26fc786d0e9308a36ff6c8e8164533d245773fd2e851f054e8aef5
font_01_sfnt_off00010d45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001255c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1255C 11148 bytes
SHA-256: f98204ec88c4f1a01b873e2ad7d2c3caf4a62189c6b67b9cdfbc5dd51d9a8e85