Malicious PDF — malware analysis report

Static analysis result for SHA-256 90558d2fec3fb9cf…

MALICIOUS

PDF

86.2 KB Created: 2021-09-06 10:27:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b7211ea6a9dab553e9e707f6d0fc5c72 SHA-1: 81328465538a635c2cd6f84a4fb37a3a7efa899b SHA-256: 90558d2fec3fb9cf4393648eab870a92d2040f2d3fbbe1228db9513e953d02e2
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent. The primary purpose appears to be directing users to potentially malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://hz-kontejnery.cz/ckfinder/userfiles/files/70790634193.pdf In PDF document text
    • http://adabaskimerkezi.com/upload/file/kesaviburazo.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/for171c54o1qtkkde8qtdi056cufnfmf/nonozipoxinabibovumuk.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/muroso.pdfIn PDF document text
    • https://dancleland.com/img/upload/file/moginiduzet.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c0fac66b5---maborenuxilet.pdfIn PDF document text
    • http://goldenbaycruisesagent.com/userfiles/file/6543639370.pdfIn PDF document text
    • http://vanlysecurity.vn/vanly/album/files/67836921146.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/ganumajanuv.pdfIn PDF document text
    • http://fairway.cc/images/blog//file/81565121436.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/g49p6hfgjagpbo6e7d8lp30sum/zasilupemiruwipikid.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fc3705478---48584713499.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e25d76e0819---gewirudamodifo.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/d55392e18fcd7e0219f8dfdb7ed68e1d/busupej.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a38e34592ba---gozunefakulopokujigorebu.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/618762f6f0760ca6521ebe84695c316a/rukifugufegevuk.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/9383625134.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/fisobimevip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=biome+map+coloring+worksheet+answersPDF 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_off0000e92b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92B 18704 bytes
SHA-256: 6ffbb84baa6d03b6dd3c2f5a6cd02a2cd7b5fc38e802ef8e5650867d948a3af9
font_01_sfnt_off0001198b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000131a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131A2 11052 bytes
SHA-256: 6c6fb5d1481252cd60e0e84c77541946a2f1bcefa7339c1268826448dac69bb9