Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfef3bb490f53f2e…

MALICIOUS

PDF

87.6 KB Created: 2021-08-11 23:36:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 1d3aa17e36e7224516d205a02f9c3f68 SHA-1: 2ef5b352498f1266bb4bc981fda7fec66edd2a60 SHA-256: cfef3bb490f53f2e2489cc46e4b505e723d5fd8cf862f735323b49857c2ab097
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://krisoc.ru/uplcv?utm_term=there+is+there+are+some+any+worksheet+pdf PDF link annotation
    • http://szentdorottyapatika.hu/files/22967123695.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/jovukelejovuxumerunapiwe.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161059ba84541c---paselisijetimopove.pdfIn PDF document text
    • http://jarosi.hu/files/file/sinaganonetidaz.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/kujodiluluxujiwolot.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1c446ed9d---64374212984.pdfIn PDF document text
    • http://samnakthodrahassob.com/userfiles/file/satumazotegadimugo.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/69826847844.pdfIn PDF document text
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/43fb304c5baf0020e6b406ab2e6da883/tivesesidigunakutot.pdfIn PDF document text
    • http://chinasoftcore.com/userfiles/file///2316708277.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608319ee32f97---pegagewosimitubaf.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d89a5d3165---suliwebanunoxazosimad.pdfIn PDF document text
    • http://kleinschaden-expert.de/userfiles/file/disafazawego.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/d0h679v1duiml7r6td77b2fngc/doweluwoxazuzexotire.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b827ae886bb---xugimabalukujabepuwusaro.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/703f94b02a4e0528727ef70ce05cfdcc/sorogapegasusejuvis.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/2d7234351c21a66052edd0110e119d93/guvozinirije.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/3m243leml2dbnj6889ne95h1h1/65386061144.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/96e85b3a3e2027339f33cd691fe9bb2f/xomuwowa.pdfIn PDF document text
    • http://dongfangguohua.com/ckfinder/userfiles/files/30704883548.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/b7b071f362c661df844e9a5e62932b31/46879752176.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/jexabovez.pdfIn PDF document text
    • http://moyamoya.center/images/hand_uploaded/files/92988056796.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/sisopevatijumixalivewuvu.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d20a43bc61add83e7d4ac34fd63916ef/jorumamup.pdfIn PDF document text
    • 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_off0000f0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A6 16980 bytes
SHA-256: 7a4c4602b42035bf82ef22a736b9adc2710c8846228a0a4eafaf4d13e798ebe1
font_01_sfnt_off00011cd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000134e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134E9 10972 bytes
SHA-256: b5e91c8e3b2d451b44024b1b0b1180b31fd8cc520cb84840c38b7b8ff8b092a4