Malicious PDF — malware analysis report

Static analysis result for SHA-256 545f9fc22d760dac…

MALICIOUS

PDF

69.0 KB Created: 2021-09-26 14:35:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cc103d2e0ecbc4c760c7c3a50048e482 SHA-1: a4a87ec4a4930038ec894ea70dd4c16587bcde38 SHA-256: 545f9fc22d760dacd499d7fd76210dfa554f764caadfe69ccd1d9efaed3e5096
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or link farms, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user consumption but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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 http://appartenvue.net/appart/upload/images/vawarutozaki.pdf
    • https://nhatthiengroup.com/files/uploaded/files/4004322535.pdf
    • http://veiligheidsslot.nl/ckfinder/userfiles/files/31831432189.pdf
    • http://misterholidaysanprisco.it/userfiles/files/99051110098.pdf
    • http://cmorshomecareassociates.org/uploaded_files/userfiles/files/ritudufopubiradudesumaf.pdf
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133c19690046---40016140589.pdf
    • https://stl-log.com/htdocs/cljr/data/files/22318168940.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1614ff8ae5109b---wujataxisisonuzalulora.pdf
    • http://keacg.com/upload/files/gosumufunadunafikonepubu.pdf
    • http://artikos.pl/userfiles/file/vekuzapolimegixakefi.pdf
    • http://muzycznescyzoryki.pl/userfiles/file/jufisosibuwizolavoxomijuv.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e87926ee4c---37714396789.pdf
    • http://babywagen24.de/userfiles/file/10392477756.pdf
    • http://www.bluefashion.cz/ckfinder/userfiles/files/49335547074.pdf
    • http://446888.top/userfiles/file/nuvenumazewi.pdf
    • http://archi-m.ru/userfiles/file/bilitorapenu.pdf
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/eab995e27c8d15fca4799ec6ac4111a7/98316306955.pdf
    • https://sicurezzaips.it/uploads/file/3212021015.pdf
    • http://electronicaindex.nl/images/uploads/nujiposesewanoz.pdf
    • http://scard.vn/app/webroot/uploads/files/kofonisuwatatabokaroku.pdf
    • http://mocphatreal.com/assets/images/ckfinder/files/sofobevanijupe.pdf
    • https://matrixx.lu/images/74290502428.pdf
    • http://remont-elektro.eu/archiv/file/zifabawimudevi.pdf
    • http://www.veslovani-vsb.cz/soubory/file/86024032492.pdf
    • http://app0.linkeo.it/ckfinder/userfiles/files/29161663942.pdf
    • http://powercleanperu.com/cms_powerclean_2015/sgi_userfiles/userfiles/files/pewaseparobanuredal.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=limbo+full+game
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b22c.bin
e4781dd70b8d81a6fabab4862cb8ab18c8f3213ba9d60fae4acda43d4ad0f068
pdf-font-stream PDF embedded font (sfnt) at offset 0xB22C 10284 bytes
font_01_sfnt_off0000c94a.bin
eb56a17e4e2049f7e615065145f0c2b8d3ee946c1736fb37d02b80c0028cfd41
pdf-font-stream PDF embedded font (sfnt) at offset 0xC94A 14932 bytes
font_02_sfnt_off0000eee2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE2 16792 bytes