Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57b4fc0f88b7746…

MALICIOUS

PDF

90.4 KB Created: 2021-09-17 11:47:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d0e0864e4c242a372222a8f5c881c5ad SHA-1: 464320de2382f612ea33a7086cda111b8efd6788 SHA-256: a57b4fc0f88b7746c24d5e767add40e99788e5f63083a50652a5324d82c1bb2a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs, such as http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16144018da9d65---2930784172.pdf, are likely intended to lead users to phishing or malware distribution sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://sutinlawkrabi.com/ckfinder/userfiles/files/rodorolagizelobimo.pdf In PDF document text
    • http://hankyunget.net/userData/board/file/zibemiwurofutix.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/60147168198.pdfIn PDF document text
    • https://alhurwallpaper.com/Files/files/baturoxawekibet.pdfIn PDF document text
    • http://okvin.org/userfiles/file/xezitubupuj.pdfIn PDF document text
    • http://profesniprukaz.cz/ckfinder/userfiles/files/11806099203.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ecd0dbfbc---xujuxabuf.pdfIn PDF document text
    • http://homespakistan.net/magzine/uploadfiles/file/3668940707.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/05f4d55771785276ac2d86cb6252500a/vojebudaboziv.pdfIn PDF document text
    • https://noriupapildu.lt/ckfinder/userfiles/files/58846272115.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/doparajegipem.pdfIn PDF document text
    • https://associazionedynamica.it/uploads/file/xejunetitef.pdfIn PDF document text
    • http://studioambienteterritorio.it/userfiles/files/24372458522.pdfIn PDF document text
    • http://retailpark.bg/uploads/wysiwyg/files/65559831594.pdfIn PDF document text
    • https://promaxsuspension.com/csmimage/file/14128736212.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/89673789031.pdfIn PDF document text
    • http://01host.ru/userfiles/files/87104241860.pdfIn PDF document text
    • http://isotope3.pm-ural.com/uploads/files/6063041896.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/riditusezogebig.pdfIn PDF document text
    • http://www.galiantsolutions.com/emailimages/file/10104442008.pdfIn PDF document text
    • https://onhimalayas.com/ckfinder/userfiles/files/dujatud.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16144018da9d65---2930784172.pdfIn PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/xuxoligutepokavakuviv.pdfIn PDF document text
    • http://minhanh.com/files/99361692711.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=ochocinco+boxing+highlightsPDF 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_off0000f6de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DE 20296 bytes
SHA-256: 1ba28fb366c8079d580c40c2602218d6f4b2068f6f64027c1de424a59b2a3649
font_01_sfnt_off00012c66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001447d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1447D 10384 bytes
SHA-256: 4500d368a76a77e6760746ce580d20bd0dedfe849f9b21702cad766422e30252