Malicious PDF — malware analysis report

Static analysis result for SHA-256 991a8938337e898a…

MALICIOUS

PDF

96.6 KB Created: 2021-07-25 06:14:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b265b6907a568f2bacfeb8b64715ec6f SHA-1: 21bbd74c210ec2dda1ea121d0288730fcfbb6feb SHA-256: 991a8938337e898aceda0d440b6f11442530a84c949f24e17a471737964574fb
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and other potentially malicious sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests these links are designed for SEO manipulation or to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://telmeed.com/web/ckfinder/userfiles/files/68187081898.pdf In PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d877934609---siverubesubori.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160daddc068de8---sofezezuriwagoxatil.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608eae72e328e---wovositerew.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4a10b74fc---nadiraditosuzawexivuz.pdfIn PDF document text
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/dbhnfd1333l0s3jg4l0mi1vs8c/51721917793.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/3bc5637339465fe4b108ad33522738de/kevobuxor.pdfIn PDF document text
    • https://dorfadvertising.com/ckfinder/userfiles/files/bifivafafotimuxi.pdfIn PDF document text
    • https://gyandeepjkss.org/userfiles/file/84696890018.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210529_45C7CAE076AF4A9A.pdfIn PDF document text
    • http://whatifitspossible.com/ckfinder/userfiles/files/60125198321.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/8bf4d38672ff17ef5f7b3a246a0900bd/navanirewofugowegen.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/laxeguvorebedukaresujapob.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/124248331760f1f99ee2124.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c63772b6b7f---dosinufi.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca1276c2b5---fusawiberusozasamudewaso.pdfIn PDF document text
    • http://smn69.com/clients/866038/File/sunabagenikamodipakoto.pdfIn PDF document text
    • http://xn--h1acbpobggs.xn--p1ai/data/files/83146563544.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160815eed54bb0---21371729393.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/d26c5e93de4c8e2a05efd232fb591227/risejetemuf.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/zebaxodib.pdfIn PDF document text
    • https://hanyauntuktesting.com/contents//files/xazidobumifonetazir.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/04cf48ed3d46c9b6a087027410229639/kojababajekefaledivasox.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a6a6b86415---24328391070.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/hfvhq53ojeqs78shadrvqr2fsg/fodakerifubojitokexoramun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=terraria+1.3+5.3+all+items+map+download+androidPDF 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_off000112a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012abb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABB 18040 bytes
SHA-256: 7a851123aba546f8f4dc32ba413e84aa0f3be8a25749e151c0884ca3a0529195
font_02_sfnt_off00015a90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A90 11028 bytes
SHA-256: 01139887e73e9115d255ae1fb42c30a7c5a78ffdcba42135868730a3ec6cba73