Malicious PDF — malware analysis report

Static analysis result for SHA-256 631da1ecbe5296c1…

MALICIOUS

PDF

80.8 KB Created: 2021-09-17 12:23:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: edb4813bd36691f7e65bddc1a5b50ddf SHA-1: 23ecfbc9c8de5bc62f32c0c3669cb0fc94d02a9f SHA-256: 631da1ecbe5296c1a56e128338fe96e13e7a36ac73b3f04561d7e58b9ac31217
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for exploiting PDF vulnerabilities or redirecting users. It also features numerous external URIs, many of which point to disposable domains, suggesting a link farm or phishing infrastructure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to lead users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://romangruszecki.com/uploaded/file/gogugafe.pdf In PDF document text
    • https://nasikampung.info/contents/files/gapegudik.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/66111401911.pdfIn PDF document text
    • https://loyallcanada.net/editor_files/file/jexamilife.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/zexebelaz.pdfIn PDF document text
    • http://chornakorn-packing.com/ckfinder/userfiles/files/bizugejijegegukidagago.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/bolakasuk.pdfIn PDF document text
    • http://e-sportis.com/images/upload/zeranaxa.pdfIn PDF document text
    • http://cuacuontoanthang.com/media/file/13442322529.pdfIn PDF document text
    • https://seikai.jp/free_images/files/junowubovisikiweburof.pdfIn PDF document text
    • http://pokebarslo.com/uploads/files/zifedaja.pdfIn PDF document text
    • https://bientannamhuy.com/wp-content/uploads/files/68633008035.pdfIn PDF document text
    • https://landatur.com/files/galeria/files/ziduziv.pdfIn PDF document text
    • http://nagymester.com/userfiles/file/dedukoxutazonobazisojezub.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/21f22fe9f3268285f784745807587e70/92981156446.pdfIn PDF document text
    • http://ibsdhc.hpds.work/ecdemo/web/js/ckfinder/files/files/gakolazoruwibubitareku.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/5500016693.pdfIn PDF document text
    • http://toanlinh.vn/upload/files/luvuwozojenazuruxud.pdfIn PDF document text
    • https://creteotels.gr/FCKeditor/userimages/file/tirojatege.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/28a34c77197ceddf2fb0ce1fd9394c41/62920821548.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/finifowubabumoxo.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/wirivutolifupojemukoz.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/60541994849.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=z+day+mod+apkPDF 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_off0000da78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA78 9984 bytes
SHA-256: 6bac61296a62d9e5c592e576b24ecff9a8191b123808a10b062d4b5d6514f177
font_01_sfnt_off0000f098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF098 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AA 17712 bytes
SHA-256: 849fa45b87550cc582d3dae2495160cc88fe1fc6b4875ca083300f1220f84399