Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac4bd664442ee0c7…

MALICIOUS

PDF

81.6 KB Created: 2021-09-23 06:11:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 79c4e1746d6b03219dd56999d873966d SHA-1: 8f48ffdf9cf9d1931a6f339b4de90ac7e97c4c30 SHA-256: ac4bd664442ee0c71d67f83a6e4f5646ad87a3c1cb68efb3fec3be5dd81c8739
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection as a phishing trojan. The presence of numerous embedded URLs pointing to potentially malicious domains suggests an attempt to redirect users to malicious sites. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ooo-kenk.ru/userfiles/file/75214145346.pdf In PDF document text
    • https://hongmao.tw/uploads/files/202109030246063292.pdfIn PDF document text
    • http://flashdisplay.net/UploadFiles/FCKeditor/20210920155712.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/45974178426.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/bizagosago.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210917_21AAA349F097ADBE.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/47539874201.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613ced302369f---81739379509.pdfIn PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/fifumerunikawewaxe.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/11009131668.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/79225961736.pdfIn PDF document text
    • https://parisnordmedical.fr/docs/file/49615025022.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/pagulemajafisiwexajaj.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/28414321286.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/84574124026.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/8424395482.pdfIn PDF document text
    • http://clevio.biz/fckUpload/file/61018849348.pdfIn PDF document text
    • http://irvine.songhakbbq.com/uploads/files/7542686198.pdfIn PDF document text
    • http://alefart.ru/admin/ckfinder/userfiles/files/82430372410.pdfIn PDF document text
    • https://noriupapildu.lt/ckfinder/userfiles/files/82088408359.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/752afb4bff5248abc33fcbf4e3a5be4b/81226514981.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/90915929593.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/sevigoved.pdfIn PDF document text
    • https://kimansion.com/uploads/file/74378048041.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=galaxy+s21+launcher+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_off0000db24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB24 10780 bytes
SHA-256: e293f905d7346fccd9c10ed798e23655dacc80c3fb7c0d63aa72d5bb17318d68
font_01_sfnt_off0000f414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF414 17036 bytes
SHA-256: 61e501e198dd5f80e5551c69452024d1f5afdbfe40a6b95a182ca161c44de84c
font_02_sfnt_off000120af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1