Malicious PDF — malware analysis report

Static analysis result for SHA-256 546bc8fd94eebe4a…

MALICIOUS

PDF

84.0 KB Created: 2021-09-18 01:34:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e0e73df3165b5240f7bbb424e7860e1b SHA-1: abe63bb5fa06a30984d7f3914ab580b59c09d2fe SHA-256: 546bc8fd94eebe4aa469ea38fe5da767cfd42893d70103e03cabd73cf33cbb9a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool, providing no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://philabc.ru/uplcv?utm_term=video+subtitle+app+for+android PDF link annotation
    • http://www.egavilanes.com/ckfinder/userfiles/files/fixosusigulukam.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/53055394935.pdfIn PDF document text
    • https://gdaniec.com/upload/files/8885591012.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/dinafatizufawebi.pdfIn PDF document text
    • http://mvdeastudio.it/userfiles/files/48501945138.pdfIn PDF document text
    • http://unseretochter.ch/images/file/44450731700.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/91093914850.pdfIn PDF document text
    • http://cachnhietwin.com/luutru/files/3714164771.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/87483033375.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16131ab82c091c---wigudubedamuromimuv.pdfIn PDF document text
    • http://cwesp.biz/upload/file/mitetomiputazela.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/xibosusojozuvawixidag.pdfIn PDF document text
    • http://matras-devison.com/upload/file/kozofewumejuwefux.pdfIn PDF document text
    • http://scsychem.com/upload/files/84916890385.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/2jitf6fdvhdb7fukif34vc5457/99046646689.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/87931325303.pdfIn PDF document text
    • http://guides2alpes.org/uploads/file/10675178538.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/nipimoxobex.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac9f5bc357---kezojenoduxafuk.pdfIn PDF document text
    • https://masini-de-ambalat.ro/images/userfiles/65389717483.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/50953691164.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/3632966021.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/bomutikezakap.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16139c3770b688---falusuzemor.pdfIn PDF document text
    • https://stopserv.ru/files/file/lodatogakemopozepivosopaw.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_off0000e620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE620 16732 bytes
SHA-256: b9e80e82c37c40ce5553db7de744e9834877d7c20ed63054a6ba2d1f018aab86
font_01_sfnt_off00011182.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11182 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012999.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12999 10700 bytes
SHA-256: 3ab3c8fa671eddda44c435e0c645d7102fb5831fda9fb8585bf5db42db53a010