Malicious PDF — malware analysis report

Static analysis result for SHA-256 8853ae875e293861…

MALICIOUS

PDF

70.6 KB Created: 2021-09-20 18:23:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f709cb77e16c0964d78638161f164d25 SHA-1: 7c9917038b0d4aef77c74f5704fd15ea98d1990f SHA-256: 8853ae875e2938618511d48800d88d16b94ee7695cb3c2329f8d26ed0e07082d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous URLs, several of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://dsfly.com/uploads/files/79096229480.pdf In PDF document text
    • http://teplolux72.ru/upload/file/3647029962.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/vapiwawagiwonisojadej.pdfIn PDF document text
    • https://ww150005.linebot.net/upfile/files/20210913014642.pdfIn PDF document text
    • http://snkpost.com/fckedit_file/file///20210903_9_16_5.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/06894a809cecb81ac0ad44705b495c0e/23706273306.pdfIn PDF document text
    • https://coverline.ro/userfiles/file/78439622929.pdfIn PDF document text
    • http://guidesdugrandlarge.fr/images/import/file/gowofo.pdfIn PDF document text
    • http://bischofs-scheune.de/userfiles/file/42901200677.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///62330157076.pdfIn PDF document text
    • http://imdmotors.com/uploadfile/file/2021090917200791.pdfIn PDF document text
    • http://bfttacg.marketsearching.com/upload/files/19596203066.pdfIn PDF document text
    • https://solener.info/ckfinder/userfiles/files/timujin.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1098360b6---vuruwadekemop.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/pugixexu.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/63496325961.pdfIn PDF document text
    • http://langfordfinancialservices.com/userfiles/files/vijeronesofasosubo.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210909_163802.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/fec85063ced16aab80b48176b30faa28/nirunemilijulabo.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/161358177d9e5b---ditutejupofa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=zaku+live+apkPDF 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_off0000b1a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1A2 17856 bytes
SHA-256: 217b01697e52df75616db2ff1bda3273d92813f2acc2c8d7c08b0e1783263e69
font_01_sfnt_off0000dfb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C6 9876 bytes
SHA-256: 3810cadb940449ba87ba1d259c9ac65ff900e54f7631ab07a99990df98a084ef