Malicious PDF — malware analysis report

Static analysis result for SHA-256 5571d6136fbbb05e…

MALICIOUS

PDF

90.7 KB Created: 2021-09-23 21:58:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eebfc86eb70872d13fe063424cdfaa92 SHA-1: 9d5d0a728fb1070a5b6f6ef0b3a97635e3ca5f17 SHA-256: 5571d6136fbbb05e9099eebda48247b1f1331c085170eccfa8158d31e85dcc86
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as a phishing trojan by ClamAV. Static analysis revealed numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The PDF document itself appears to be malformed or obfuscated, with no readable content, but the presence of external links indicates an attempt to lead the user to malicious content.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.2981

Heuristics 5

  • 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
  • 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://crysiq.ru/uplcv?utm_term=samsung+note+3+android+version
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161476d679dc9c---80263037876.pdf
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/6tuot9tceb7n3ctr6s9re0vv10/bodufugakuru.pdf
    • http://exdebt.bg/userfiles/file/butajilolapuninakepon.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad4cadf0ff---7807137893.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132a9e4b5731---dofizezitujedaporux.pdf
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/18649682467.pdf
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/lapobesibadenopuz.pdf
    • https://nnkcreations.com/userfiles/file/fewozepakuwap.pdf
    • https://smartstone.ca/userfiles/files/25054108553.pdf
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/zogetamivegamujafaxave.pdf
    • http://veterinariomauracotti.it/userfiles/files/21342008284.pdf
    • http://marymo.ru/uploads/files/30061688168.pdf
    • http://darstin.com/userfiles/files/83600001209.pdf
    • https://bibonatura.com/ckfinder/userfiles/files/7040249265.pdf
    • http://vaynhe.com/upload/files/kigavidewegalelipugutad.pdf
    • http://yakutiaprime.ru/SITE/files/editor/file/68335373903.pdf
    • http://bibikid.ru/upload/21745739097.pdf
    • http://cuboni.com/uploadfile/hong202109022316558822.pdf
    • http://hyundai-dongdo.vn/images/files/buxurokowaxasafezimofu.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16130591074a40---28460259653.pdf
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/viporan.pdf
    • http://pastadimatteo.com/ckfinder/userfiles/files/pekoredinisukatatu.pdf
    • https://emailing-online.fr/uploads/userfiles/file/18290178203.pdf
    • http://nemalipics.com/26114781910.pdf
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010dda.bin
30d850b6e95fa19d16da4c5bfd8d0c23b3c62d83566d4f26cdb18af3ba7e7475
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DDA 10956 bytes
font_01_sfnt_off00012712.bin
a7f426ba22565b1703ab33aefb6668e3d3122a051ed10efb06d3457b730f43f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x12712 17984 bytes
font_02_sfnt_off0001563d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1563D 16792 bytes