Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf6128a3f45e2c60…

MALICIOUS

PDF

74.8 KB Created: 2021-08-24 09:06:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7d4bd1d2809958a4dc0910215f59464c SHA-1: 1993b410e773857fd8cb2a78222892ff89e2abc8 SHA-256: cf6128a3f45e2c609a14cbfcd4a9ff0e594723ef4a932d14bb486e1f321348ad
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to various websites, including those hosted on compromised CMS platforms. This suggests an attempt to lure users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8706

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://synergytaekwondo.com/click2buy_newp/userfiles/file/29945732552.pdf In PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e50c7c2cb34---xofuna.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/fa6163ba1e1e4ca550e7975a353879c2/46338297801.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1622316308.pdfIn PDF document text
    • https://www.koreayokogawa.com/ckfinder/userfiles/files/50246922710.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/83916923339.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/tedagodadelewulazewagebip.pdfIn PDF document text
    • http://mamtomchabahai.com/uploads/files/files/nujubetonuvitotobid.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608a82b8139b5---dafusanubixariw.pdfIn PDF document text
    • http://sluchatka-shop.cz/files/upload/files/43036594132.pdfIn PDF document text
    • https://biovuspharma.net/userfiles/files/32883222021.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/0e73fff40bf8234b2244a57f13f67951/27390609816.pdfIn PDF document text
    • http://mt-filtration.com/uploaded/file/165762371560d1eb6abe261.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5c286f18c90bba4699bc924294ee2b7b/zilirosa.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/ladujilujagerobinut.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16104315e218cb---99453543072.pdfIn PDF document text
    • http://kaies.cn/upfiles/file/ziveloliw.pdfIn PDF document text
    • http://eurolocal.info/sites/default/files/images/file/sofofesito.pdfIn PDF document text
    • http://bckbytow.naszbip.pl/img/upload/files/58971860109.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092cf3a8b6e6---dudaruxubinexanidazu.pdfIn PDF document text
    • http://anshan56.cn/userfiles/file/16297679871292942265.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/e38cfd6d08065ee7054c900fa082e68d/xikawawi.pdfIn PDF document text
    • http://ffarchitettura.it/userfiles/files/96276095199.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=dredging+and+maritime+management+saPDF link annotation
    • 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_off0000cda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA9 10424 bytes
SHA-256: 585dee4c9f4ef9439c839ed1dd4b16305af389010802d4038f962142b9076adb
font_01_sfnt_off0000e510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE510 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD22 17396 bytes
SHA-256: 178d157e61d52a62834106c2d9c0ff7169ce6787cd0369047f20d20c27c1536a