Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b66ef4bd6b4df99…

MALICIOUS

PDF

80.9 KB Created: 2021-08-16 11:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d3252dd59e68196fa527faee9ca10eca SHA-1: 0866e973b0bc7346216b43c280c0f4121d661d6a SHA-256: 8b66ef4bd6b4df99a7dbc706dcf7aee7d4c31dd2084cb29e762307534220cd55
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it's designed to exploit vulnerabilities or trick users into visiting these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/uplcv?utm_term=why+does+my+nescafe+dolce+gusto+leak PDF link annotation
    • http://esthebel.de/userfiles/file/91472273320.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/4674889084.pdfIn PDF document text
    • http://martonelektro.hu/files/file/fidugos.pdfIn PDF document text
    • https://addsfly.com/userfiles/file/69355505122.pdfIn PDF document text
    • https://areicon.com/images/file/55303449354.pdfIn PDF document text
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/20038c727628bd9706b492800b82aef7/zevumumifamulurudipa.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/6adb83c446af41a5dd2dbda3460e45aa/63077368575.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160c76ac3c5687---75659177376.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/65292053933.pdfIn PDF document text
    • http://studioriggio.it/userfiles/files/63713072138.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f05fb0d58c---wosonuvozofufidex.pdfIn PDF document text
    • https://33mobility.net/uploads/files/radanexunogaxewaj.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607d4c927d180---99625461425.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/midabezopuvon.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/kukoze.pdfIn PDF document text
    • https://eurouniversal.eu/ckfinder/userfiles/files/safedokelugob.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/t168eip3uqh9r19m6tmn38b410/sisowava.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/39313969384.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/vamowupifixozupipezi.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/44351269131.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_off0000da47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF259 16320 bytes
SHA-256: ac349c4e27e20663b22546448e7e974393741bd332691b23fe478415bba7aa74
font_02_sfnt_off00011c45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C45 11028 bytes
SHA-256: bfe75d53e556984ade8abf874d5c4007557ead469d914f4583aa1f67ff284940