Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6d9b6142fca7c8c…

MALICIOUS

PDF

77.1 KB Created: 2021-09-24 10:59:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2158d0d137b061f21f18c6a0468b9ede SHA-1: ffe51ada46a441ba4f0cb52826825aa326e3b35b SHA-256: a6d9b6142fca7c8c861545b3e378bba11dc2bd38160221cf6fc3b9f875534223
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of numerous unknown URLs further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/16fjtkpjsv1s2nnvv29m5ghpq6/67907550240.pdf In PDF document text
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/14306046116.pdfIn PDF document text
    • http://hostingureitings.lv/uploads/userfiles/files/31018562277.pdfIn PDF document text
    • http://yilbasipromosyonu.com/userfiles/file/binez.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/wejelezewe.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/lurufo.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/84883575293.pdfIn PDF document text
    • http://jlsxjy.com/right/UploadFile/file///2021091316055173499.pdfIn PDF document text
    • http://maekalocal.com/Maeka/UserFiles/File/zubebavepugadikun.pdfIn PDF document text
    • http://www.siposferenc.hu/html/fuzomomuzo.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/5ef5e9f6b1e54298543892ed6eac7ec4/90575966886.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/39640928174.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/85164274111.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/divumafukorin.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/fuzol.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/tomijetigulogusowojuxe.pdfIn PDF document text
    • http://europavloeren.nl/siteimages/file/kejunefomevibavubopojuf.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/703923771811724d1adb86530bee7764/dabix.pdfIn PDF document text
    • http://neodentpetrosino.it/userfiles/files/dofizujumel.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/92222331253.pdfIn PDF document text
    • http://anindecor.pl/files/file/3579064984.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/wibovizanigisu.pdfIn PDF document text
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/5427487535.pdfIn PDF document text
    • http://htwy.com/upload/file/34104239313.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=running+windows+programs+on+androidPDF 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_off0000c90a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC90A 10688 bytes
SHA-256: 2d83e8d05fd01dcbac208e709a2d89ec2f7bd6ee04621d0667f17e960dea1436
font_01_sfnt_off0000e156.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE156 17352 bytes
SHA-256: 8d25ffec87a5a92ccfd9a5b09b90d35ce8cd0d3db74837d3288176a6a836695a
font_02_sfnt_off00010e77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E77 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1