Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf99ca3fdd88e3d…

MALICIOUS

PDF

71.7 KB Created: 2021-09-16 20:42:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3ed65443a685c37f636eefa7a9f05e87 SHA-1: e18d607ae716e3f10d8f2d26e2cad0911054dc02 SHA-256: caf99ca3fdd88e3db3e7ba5b77860fab9cb141cd89ca58239118e55a309164c0
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the finding that the document is a link farm on potentially untrustworthy hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://hilimall.ae/uploads/files/57505219481.pdf In PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/rqudjrpdhkt2dodhtqkk6vllmo/gizakar.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/2498302072.pdfIn PDF document text
    • http://stroi-sistema.ru/img/jilubujo.pdfIn PDF document text
    • https://songhong.info/userfiles/file/10976890074.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/2894173490.pdfIn PDF document text
    • http://studioingtassinari.eu/userfiles/files/rojewejiroj.pdfIn PDF document text
    • http://csc0532.com/userfiles/file/20210904072921_12tklt.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/27807587058.pdfIn PDF document text
    • http://antichigelsi.it/userfiles/files/22537211874.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631073714.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/74d86a23eca1bba74581eb26e0466ee5/77817288451.pdfIn PDF document text
    • http://gazetavk.ru/img/file/xevebulifez.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/34245870053.pdfIn PDF document text
    • http://saimiri.name/upload/file/lorosufonavozuzefigewoli.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/61908455432.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/fasekololuw.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/89201228820.pdfIn PDF document text
    • https://www.serwkom.pl/plugins/ckfinder/userfiles/files/mowerewifasotukovo.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-9-9/20210909221535656753.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/71847303416.pdfIn PDF document text
    • http://ty-int.com/files/files/6380884101.pdfIn PDF document text
    • http://www.smartusb.info/images/library/File/widaribe.pdfIn PDF document text
    • http://brain-sh.tw/upload/file/74753158704.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5ab3216be---32136873082.pdfIn PDF document text
    • http://badgerhillfarm.uk/kumim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=faithful+departed+40+days+after+death+prayerPDF 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_off0000b78b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB78B 15696 bytes
SHA-256: f664872e119ac8d0e2ef5b927623a2a884989394074f2c4cdaaca159f921b524
font_01_sfnt_off0000dfc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC6 10764 bytes
SHA-256: dff6833421c462d5c95c78529376be03ae2d0f8ffe108407efc68723fc7bd86a
font_02_sfnt_off0000f8b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1