Malicious PDF — malware analysis report

Static analysis result for SHA-256 f53db8053ecc2395…

MALICIOUS

PDF

83.9 KB Created: 2021-09-21 15:37:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 98acaa7ed6a719117564addf3e61883a SHA-1: 92901bcd47a6f35ef08e178c2b4bf471e941c2db SHA-256: f53db8053ecc23958e194a4a19ee35ce7ad643691bc9f8aa04b9ec5d60be77ef
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, a common tactic for phishing or distributing further malware. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards an attack pattern involving redirection to malicious sites, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://huntic.ru/uplcv?utm_term=using+your+phone+as+a+webcam+for+computer PDF link annotation
    • http://aodaiminhhanh.com/app/webroot/uploads/files/64245483560.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210911203357.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/xelunifotawubevapipaxu.pdfIn PDF document text
    • http://woodlander.sk/grafika/file/naxuzetap.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/sozumebomifo.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/9987947600.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/14017795059.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/70849110829.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/sulagisigiwezasisemorote.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/rojenuzuvukuvonojalile.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/gobizuja.pdfIn PDF document text
    • http://dodogs.ru/sites/default/files/file/5315001328.pdfIn PDF document text
    • http://kubkao-kubpla.com/userfiles/files/29944306126.pdfIn PDF document text
    • http://intertravel.hu/_user/file/31730142378.pdfIn PDF document text
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/ninoxukizexedipiv.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614809a6c0e82---13501094999.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/22404663293.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/vogisoxoniwudad.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/58136712489.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/deduzaf.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/492972.pdfIn PDF document text
    • https://salonrewards.ca/images/file/36431817020.pdfIn PDF document text
    • http://businessplan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/dojezejotanoruva.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/wulidotuderogisa.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/10142264964.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/12375095714.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/data/editor/file/69966924061.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e27bec5018---sudidaluvukuziduriza.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_off0000dfdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDC 17968 bytes
SHA-256: 6ef6fe81f62a0f3b37b140a0ef081c34ad0fa1224a7c8a3f638cf7d1f62c7953
font_01_sfnt_off00010e93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000126aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126AA 11328 bytes
SHA-256: 713747c570044d941c46f1da60d5ee25666f100938757e70930044d833c6a636