Malicious PDF — malware analysis report

Static analysis result for SHA-256 91bfcc5f914611b6…

MALICIOUS

PDF

84.6 KB Created: 2021-09-03 06:52:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: aea7adb32c2b9f36a14dc654decaef0e SHA-1: 92b8a228528c12a40e8fbb713bfde8efa1f6465b SHA-256: 91bfcc5f914611b62aad217a83164213713c9693080dd5cacb40adedf341f706
176 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious content. It functions as a link farm, directing users to numerous unknown URLs, some hosted on compromised CMS uploads. The 'SE_CALLBACK_LURE' heuristic suggests a phishing or tech-support scam pretext, aiming to trick users into interacting with malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • 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.
  • 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://congseng.com/uploadfile/files/99054552092.pdf In PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/0cb959a2a6bd56ad39f26d29448b4ccd/87214581490.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/78542425169.pdfIn PDF document text
    • https://www.sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/16085c292b7212---dexujedupotinovabi.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/tojezajajosebowapufis.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794c669a152---43176420684.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/xamitizesuxikisaluduf.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/xofumaludakal.pdfIn PDF document text
    • https://rendszergazda-cegeknek.hu/ckfinder/userfiles/files/jaxedolug.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/4350659383.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160825b5559e48---2462279993.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4c70c396d---35880772673.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16085495b3298f---51531738367.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/2ksut2b0j12msu3jpkkj6npunk/25204661665.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/rugenosonijotixateje.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608323e05f6c6---wudowex.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/39632675228.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/29005000751.pdfIn PDF document text
    • http://nova-auto.com/upload/20458303603.pdfIn PDF document text
    • https://netiko.ge/img/Data/file/lewumakituba.pdfIn PDF document text
    • https://vinacoma3.vn/userfiles/file/73971703490.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/18623799934.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=dogar%27s+unique+books+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_off0000e387.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE387 18616 bytes
SHA-256: d111f4313206010839379ea1ead486efbc26925e6720817f8241b6ce6c6a16c1
font_01_sfnt_off000113e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012bff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BFF 11040 bytes
SHA-256: 3d6a2caa81a3192766452360d671605c200e4ce3c5b09d4f721559157774ce78