Malicious PDF — malware analysis report

Static analysis result for SHA-256 62637b65e9e2d057…

MALICIOUS

PDF

87.4 KB Created: 2021-09-04 02:34:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8ab884f8ed3cabc917621fee1a613a35 SHA-1: 05cc27bd404dda184499d4284de05d6875dcaa16 SHA-256: 62637b65e9e2d0574496e936fe6dde346b48516d73919d4f0988f556d107e005
156 Risk Score

Malware Insights

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

The PDF file contains a link farm, directing users to multiple external URLs, some of which are hosted on compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://shengnabei.com/uploadfile/file///2021060806465197.pdf In PDF document text
    • http://beloit1962.com/clients/8/83/8368a4f838dea3176655029ae9e337da/File/87569960445.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edb78baa1c1---43364549862.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b956844f025---takuratuzivifepoziwos.pdfIn PDF document text
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/3fdg9hkldoqi97it0vh6iai1kp/figixuzuxigol.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16091004fec975---bikofoke.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/wotuwawuf.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4010170287---wikat.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/b168e8f20b94ab808b0fb8c1e91e4bb6/14346437678.pdfIn PDF document text
    • http://ogbchurch.com/clients/880797/File/folosos.pdfIn PDF document text
    • http://att-na.com/upload/rakezeragivufa.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc0bc3c5eb2---gijovusute.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/964638b21e01b354a332117f65513817/32515878244.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/7d31fc04979417eee3e02d1349f96016/98302861480.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/b083f2db6f68e2ddb6a5d9b36813bd57/605070432.pdfIn PDF document text
    • https://appfacile.it/file/40756236703.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160854bbb1d99f---56109623024.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/eb8c2fca407a66dd67abb7bee008fed2/91554259977.pdfIn PDF document text
    • https://stopserv.ru/files/file/68239831030.pdfIn PDF document text
    • http://abwhopewell.com/uploads/files/sefek.pdfIn PDF document text
    • http://stphilomenaonline.org/userfiles/file/77662202659.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5cd9ea58fe---14858038921.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/io8l6ltqbdljhqkf0dan1rpaj4/96284764761.pdfIn PDF document text
    • https://summit-christian-academy.com/scauserfiles/files/41383825016.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=garmin+62st+manual+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_off0000f050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF050 18004 bytes
SHA-256: 85da2d59c223411d5589691b3ba4ac6a6ae1d9195c3fa95145ec7a93cdeb025a
font_01_sfnt_off00011ec3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC3 10832 bytes
SHA-256: b47640f7526a023d5d537b52cad175b645089f8621c56e912ef0ed145791abcc
font_02_sfnt_off000137d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1