Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a1660fd8521cdca…

MALICIOUS

PDF

95.4 KB Created: 2021-07-01 10:03:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 02491f42fd435cc67868cdda3cedc091 SHA-1: 8b046484adaa2507ad9f9fb4452a65d3ef7655c0 SHA-256: 6a1660fd8521cdcab24955ec17f6d77ca17b4161d9f0b5b7baceba02472b36e9
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites, likely to distribute further malware or phishing content. The presence of numerous unknown URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608761f583aa6---gulufibuveruzuk.pdf
    • http://exmar.it/foto_fck/file/tapofuzuvegufatob.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160a722e4e8c3b---nupupidosuxelafizi.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/d7b273388b045f294f7ba5cb67ca7b72/numolufe.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ba6477b63---sulumijewebujusedupemazug.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/c7ab79f5ce757be9ec6cd701eca01e47/suduwojuxawoxafega.pdf
    • http://www.heksan.com.pl/file/luwifexeza.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/f66159509737363464850448c07d695b/84164892175.pdf
    • http://mikomisushiwc.com/uploads/files/84428451700.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c080912430f---zavusuze.pdf
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a4247634033---21563659341.pdf
    • https://moto-trend.cz/public/files/fck/file/71793027722.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16074061ef234a---mefetobotikuf.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1899b992fd---68360361410.pdf
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/29090e1d87524364b1b624536d79e74f/40070686750.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ac1923792---19320731994.pdf
    • http://inventory-acepipe.com/images/uploads/files/lijoriwulevupedax.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608611340659b---butujipuzunimiduzoli.pdf
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b009f2b3e8---jibibaworof.pdf
    • http://udokutscher.de/gfx/userfiles/files/teparemozilefeli.pdf
    • https://dvg.asia/ckfinder/uploadfiles/files/mepefokavomatixekoko.pdf
    • https://dubaimotorcycletours.com/uploaded_images/files/rerupivuxewedixa.pdf
    • http://rebizplus.com/userfiles/file/77846014901.pdf
    • http://bestapp4u.com/admin/uploadedfiles/file/59223486905.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=download+buku+harry+potter+and+the+cursed+child+sub+indo
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • 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_off00010fdc.bin
394fa439a4144fc85a7048fb1bd4fbd156c3dca03373fdd0b75350017f7e93be
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FDC 11144 bytes
font_01_sfnt_off000129ae.bin
af96073a8d4d8b1f1891316dffc55fbcfbfcae200fd7b0b9e9dddd58f9984059
pdf-font-stream PDF embedded font (sfnt) at offset 0x129AE 17816 bytes
font_02_sfnt_off00015787.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15787 16792 bytes