Malicious PDF — malware analysis report

Static analysis result for SHA-256 820bf5295ea1d687…

MALICIOUS

PDF

82.1 KB Created: 2021-08-18 12:21:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4852ec671b939f0e4f7708f725bde1f4 SHA-1: f6f596a6b4dfdbb3094d329c230548a86a063f09 SHA-256: 820bf5295ea1d68793e6d8e876c99024d14c2134d39a27c89feac580f47e1b5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs, many of which point to potentially compromised CMS upload directories or are part of link farms on disposable hosting. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics suggest an intent to redirect users to malicious sites, aligning with phishing or malware delivery tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.alex-vasilkov.ru/images/wisdom/file/2543001378.pdf In PDF document text
    • http://xn--80aafbanafwvcftiqfecrg2a.xn--p1ai/pict/file/74375562398.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/8d76fc4178372a3f6e5d8c009fbf6aad/zupasotegaxanesekedat.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/26783769920.pdfIn PDF document text
    • https://dintek.eu/uploads/file/96071340470.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/n1n7itnd9fg044k7fhaluvcnaa/9268683754.pdfIn PDF document text
    • http://93564497.com/userfiles/77454950385.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd67a3ea7a---22959680836.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/zisub.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/porawukebutepopaworowabor.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/nntsm793vutn1fpsvqqglp5jj7/46477087837.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/5gqv8aeak1g9kka7tehci67aq6/75213132787.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610e7219e8c8f---87997921508.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/77999224668.pdfIn PDF document text
    • http://nhasachthunam.com/upload/files/funapanolabidivezatovoza.pdfIn PDF document text
    • http://dyweisheng.com/uploadfile/file/2021072411031773499.pdfIn PDF document text
    • http://riverbendhay.com/clients/4/4e/4e1cbd84181290ddb66fb035c9950ff6/File/50292020831.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7a831d0ff---63787926251.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8e6139aba---tuduxonow.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609b30657c633---vinikavutagozid.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/mvs38j76tgb8r3f46e4m41bqgp/64756584331.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202108052203107005.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/3141047505.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16093c2c657a8f---96686270933.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+build+muscle+at+homePDF 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_off0000de4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4C 16396 bytes
SHA-256: c2ff6bbf7ff9a62c69bfbcbdeb04025157c434fe095a39873b0745d33ef14a15
font_01_sfnt_off0001085c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1085C 10748 bytes
SHA-256: ceb1ef1998747d748b0c58d533f9cb73a5dcebfbd4f0f84524ee4b9098050838
font_02_sfnt_off00012123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12123 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1