Malicious PDF — malware analysis report

Static analysis result for SHA-256 255c98529725f9c6…

MALICIOUS

PDF

82.9 KB Created: 2021-09-03 10:05:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b94b5d6e7596ad06e7975fb0ac188c58 SHA-1: 59d641d743ddc92390a6519738dd6dfbaf18b3ff SHA-256: 255c98529725f9c6062aa245180fb87a59d9414b4121faa8fc7c62dd08bee8dd
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a callback-phone (TOAD) lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160926aef44562---bumifiliruvifa.pdf In PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cca1dd86a3---lefexasutumukugotaka.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/xifivepufafuseganuzedom.pdfIn PDF document text
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/80601765475.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///15726198443.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c8d887271---wutikimesazasixekabaja.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/lolowoxogi.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/87f7d62292df4b3b4ebfc95880bf8d6c/84088977139.pdfIn PDF document text
    • http://solac.nl/app/webroot/files/userfiles/files/42206801193.pdfIn PDF document text
    • http://smart-ventures.ch/upload/Editor_Images/files/gujaxolozejuxe.pdfIn PDF document text
    • http://aviteksural.ru/admin/ckfinder/userfiles/files/13996287319.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd5ce6d6ef---jegetinolusijutonebekob.pdfIn PDF document text
    • http://rilta.net/userfiles/files/33696074792.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/38464765014.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/79057666528.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/wijuromojet.pdfIn PDF document text
    • http://design-klasse.de/ckfinder/userfiles/files/lagetikonapadeke.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607542a71399c---15604754096.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/pilonatupowutikunidi.pdfIn PDF document text
    • https://banktapeunadana.com/tapeunadana/bank2/admin/userfiles/file/63634415759.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/1f5e37a24f02f7cf397d65170caf28ee/letubuf.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a986d2ae526---24111565059.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/rirujakirejebupolubuz.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/ede1a72cd4c40e9dd26737654ad93a1a/62890292993.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/96b145f535376933d719e1cc004561de/52826883043.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/51976293412.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/ebde500e66c403ca5eb3893f6498799a/97014479350.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=naya+pakistan+housing+scheme+karachi+form+download+pdfPDF 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_off0000dbc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC9 18080 bytes
SHA-256: 3c4e1f37475334019af123a78ef86da0d3ee550db98eb81712e301ada299786d
font_01_sfnt_off00010a84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A84 11436 bytes
SHA-256: 34be7c9f0da2f9cc5034767eb09aab34f9315a155c17bb2135b36cc2167d8655
font_02_sfnt_off00012540.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12540 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1