Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1599806294368c…

MALICIOUS

PDF

88.1 KB Created: 2021-09-07 15:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1902a63bda00d082c004d6a222f5e55e SHA-1: 31c8f1d4fcbef79225ce2be60bcc1f19d635371f SHA-256: 4b1599806294368c6cfeea22d435f92e24d105cdf276e73f9762e9211aa4cc2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads. The PDF document itself contains obfuscated content, but the presence of numerous links to potentially compromised sites suggests a phishing or redirection scheme. No scripts were extracted, but the PDF structure and URL patterns are indicative of a malicious document.

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 http://toyotarentcar.net/FileData/ckfinder/files/20210630_1803D260961252DF.pdf In PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/1af447bc837b003264da7d6254b134fc/82829390801.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160840af2239a8---kexawixowuziludi.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607edf4c8f0fd---51493539260.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/9517690566.pdfIn PDF document text
    • http://www.ks-klinika.ru/ckfinder/userfiles/files/4518739114.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/161324a3d7d9d0---88537934986.pdfIn PDF document text
    • http://relocationservicesgroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7211dbc5b---1234554414.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/30252691235.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16121723e3def4---bazunibubolaxi.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607359fe0430f---37480766417.pdfIn PDF document text
    • http://turatabor.hu/media/pazaxaxanuxat.pdfIn PDF document text
    • https://psihodesk.ro/ckfinder/userfiles/files/45892623278.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/gbktnjlh32vab2871ud6jnk047/kojetelipajodigeli.pdfIn PDF document text
    • http://c-six.it/userfiles/files/90632546673.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/145233760660d1f781b1c5a.pdfIn PDF document text
    • http://petrduchek.com/files/lofulararosirupulisame.pdfIn PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160776c80b478d---33431788128.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b0e374d16e4---rukejakovifotalika.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/e68e03c65c92c3b821b20d3d2decf92c/87752245252.pdfIn PDF document text
    • http://24cvety.ru/upload/files/mogefezopomolarevojirugeb.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/88030374022.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e3489e035e3---96209529407.pdfIn PDF document text
    • https://uclerbaklava.com/resources/file/26527293471.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=fleur+du+mal+baudelaire+pdfPDF 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_off0000ed0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001051c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1051C 21628 bytes
SHA-256: 02e75dcefaf87475f14b89645af97ff44a7706a017d8d5bda8b15c4cda0ace0f
font_02_sfnt_off00013b92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B92 10388 bytes
SHA-256: 1f8aaa516bc0b0d86480ee03733792f0751069cdde32b89793c11c1a405a1120