Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ef99cd99f0c21e0…

MALICIOUS

PDF

67.5 KB Created: 2021-09-16 12:16:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 63894d754a5ca27207a5bf06725c8835 SHA-1: 3001490c08f175c5db81de06041ddfae5f43215a SHA-256: 8ef99cd99f0c21e04ca28bcb8929c5ada126480180166d3dddc8148d1f8ee8a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing a large number of embedded URLs, many of which point to domains associated with link farms or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://crewmak.ru/uplcv?utm_term=how+to+turn+off+download+over+wifi+only+android PDF link annotation
    • http://materialdeestudo.top/userfiles/files/wovibekuluwapokub.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/ximesewevunoguxewonuruse.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137ad9e78d70---36579649597.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/rukefejofezefusiwob.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/zizerazemusapojiso.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/4401674189.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/nisonerifariduk.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/94092d8e892bec1e039dc0639566a730/26408042664.pdfIn PDF document text
    • http://safarang.com/basefile/files/48499846338.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/b427bd425518fe96fa19cb05ef289edb/31632931349.pdfIn PDF document text
    • http://020tzs.com/baige/images/userfiles/file/84809663246.pdfIn PDF document text
    • http://propack-th.com/image/upload/File/31187579218.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377ed9e974c---tafenutojajojetegaf.pdfIn PDF document text
    • http://rc-modeller.se/images/file///xuxokezudugaju.pdfIn PDF document text
    • http://sabaispa.net/userfiles/file/2067620099.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/11491281254.pdfIn PDF document text
    • http://chongthamphucthang.com/images/news/files/gadexikokisibepiluteferex.pdfIn PDF document text
    • http://redactron.com/userfiles/file/wiwof.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/werirezafokadijexe.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/15760046404.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/xatinawa.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_off0000ad0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD0B 14292 bytes
SHA-256: 55c2a560030e35e0b1942806a1d4cb3ed260ed5f6c1f9b34bee3e6665f2974c2
font_01_sfnt_off0000d07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD07E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE895 10536 bytes
SHA-256: 1794b503379c0f83f24e7a1df1a12fcb32d8b571ce41101edd2764d71ece9bb1