Malicious PDF — malware analysis report

Static analysis result for SHA-256 548ef5bc7f9f807a…

MALICIOUS

PDF

87.8 KB Created: 2021-09-13 11:59:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d90a093ed49be073f7c282fdc09b809e SHA-1: febde2398ed50fc2792e3671583675f134714f00 SHA-256: 548ef5bc7f9f807a2b3a2cd0476d2c7a37f25e744ee349fe9b0dddf61f97df31
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://otelm4b.ru/admin/ckfinder/userfiles/files/fuluse.pdf In PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/8b2655819a73266311ae3e509a626550/97024709311.pdfIn PDF document text
    • http://xedaphcm.com/luutru/files/96017470334.pdfIn PDF document text
    • http://huynhgiabaohotel.com/uploads/FCK/file/74644623870.pdfIn PDF document text
    • https://tradingphrases.com/userfiles/files/xopabifadamanobivatuxovum.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/16652719717.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/d6582c577bca37dde275e047df59b805/xilezapowaxeso.pdfIn PDF document text
    • https://coastalholidayproperty.com/ckfinder/userfiles/files/7621138822.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/67514193837.pdfIn PDF document text
    • https://ksuskalology.com/images/file/pupolaziwofexowubirezonis.pdfIn PDF document text
    • http://nensi.si/upload/file/13074146765.pdfIn PDF document text
    • https://kaparatt.com/images/File/mozajuvakor.pdfIn PDF document text
    • http://administratieindex.nl/images/uploads/76449081169.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/wezazebuxiwifo.pdfIn PDF document text
    • https://medbillings.us/lightspeedweb1/file/44155676362.pdfIn PDF document text
    • https://clubsecurite.fr/webroot/upload/files/togur.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/161330c51753c1---95783749177.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/pm1uleoie0luolbig2tmfbqku0/devizeredewigubopajepofi.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/vegoteraluf.pdfIn PDF document text
    • http://on-video.com/movies/movie_data/file/bokexoga.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/lofodilokuguge.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210907063107.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/92184216433.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=best+facetime+app+for+android+to+iphonePDF 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_off0000ed70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED70 10892 bytes
SHA-256: 2e074bcd1046ace86de9f1ac27f5089e3c4815acb8a6965ab1ee4e5c8734901f
font_01_sfnt_off0001066c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1066C 19600 bytes
SHA-256: b5842655fbf3169493f34daacb418b3721ba4b5d146af2178312ed2fce778cfa
font_02_sfnt_off00013954.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13954 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1