Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5f861d885d224f4…

MALICIOUS

PDF

72.8 KB Created: 2021-09-18 20:13:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1b31352641edbddafa2f32045fef5f90 SHA-1: c635e1c942113b4d267dcb1176d1c526f7aa99f8 SHA-256: d5f861d885d224f416c36a618dc9d2a2e9b1d04dcc1aefc477ffacc2571f7637
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with high-confidence heuristics indicating it's a link farm on disposable hosting. The embedded URLs, such as 'https://chcial.ru/uplcv?utm_term=supercloud+music+downloader', suggest a lure to external content. While no scripts were explicitly extracted, the PDF structure and heuristic findings point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://chcial.ru/uplcv?utm_term=supercloud+music+downloader PDF link annotation
    • https://dgssu.com/upfolder/e/files/20210909060258.pdfIn PDF document text
    • https://cevhertemizlik.com/userfiles/files/89834979381.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/74699493146.pdfIn PDF document text
    • http://justsayhi365.com/uploads/file/90692939682.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/48856342543.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/261a1e57276b90a263c2e5c74d0bacd9/vuxaripikifat.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/61002761035.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/69055979790.pdfIn PDF document text
    • http://karlsbach.de/userfiles/files/kadirikew.pdfIn PDF document text
    • https://eastmangroupllc.net/ckfinder/userfiles/files/lizuxoxumol.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/fugufuvapisupaja.pdfIn PDF document text
    • https://stichtingech.org/ckfinder/userfiles/files/11362586246.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/napubimutafuxojexowu.pdfIn PDF document text
    • http://ms-domino.eu/images/file/files/piralazebesux.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/14886989216.pdfIn PDF document text
    • https://a-pointpro.com/cms/ckfinder/userfiles/files/vajeronabafe.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/ronoze.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/kodizipakeb.pdfIn PDF document text
    • http://www.galiantsolutions.com/emailimages/file/16343268942.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/62988914615.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/mefuvufejegarinof.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f9930e5d6---61397050962.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210917_27B1D7490B34EA95.pdfIn PDF document text
    • https://davidfauquemberg.com/home/fauquemb/david/bbdg_site/userfiles/file/79353114977.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_off0000ba60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA60 16240 bytes
SHA-256: 203c9845d3334c6488c72648552ac65db8103cb683c9a96c9cc7a251e327e3d9
font_01_sfnt_off0000e441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE441 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC58 10836 bytes
SHA-256: 58f894340a65a3e6a4112bfcf6c75ef91350873a005df360d71cf99114d58a3a