Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8b3d6381e0ece29…

MALICIOUS

PDF

80.9 KB Created: 2021-09-23 18:14:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 886e2d928ac0037a33ffcf832ffad541 SHA-1: aadce335a8418bee5a0c44f811728a75d3624bd5 SHA-256: c8b3d6381e0ece29557f367acf12fcd2d46f7c51675c4fcb371c5fc69af48f5f
156 Risk Score

Malware Insights

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

The file is a PDF containing a link farm that points to multiple other PDF files hosted on compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of numerous links on disposable or compromised hosting reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/ecf0ecacf9d242376965f8a447fd3452/vevomalulebodiw.pdf In PDF document text
    • http://nicolalazzarotto.com/userfiles/files/93893410274.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/87575339636.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a62ed2a5f---28006707177.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/79314354206.pdfIn PDF document text
    • http://budropol.de/Upload/file/pufafulobunizenonisunabux.pdfIn PDF document text
    • https://snf.styleguides.ch/userfiles/files/24746554700.pdfIn PDF document text
    • http://kbchina.de/upload/zoledezasumurigebuno.pdfIn PDF document text
    • http://stagegator.scorchmark.com/stagegator/ckfinder/userfiles/files/lokirox.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c1abdc8702---dabirebidajurawilitixe.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/lirexavezezaxanofexin.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/e125cf17fad3fe4547a6a4f35a7d9a00/vowesol.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/dojoxamawepamofediji.pdfIn PDF document text
    • http://union-montage.pl/userfiles/file/risokiba.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/mobabisifodet.pdfIn PDF document text
    • http://temple.mo/userfiles/file/52570310367.pdfIn PDF document text
    • http://xn--80aer5aza.xn--7-4tbj3b.xn--p1ai/ckfinder/userfiles/files/59983931746.pdfIn PDF document text
    • http://dienlanhlongan.com/upload/files/rodiwagimoko.pdfIn PDF document text
    • http://scsytech.com/upload/files/95228542116.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613dccfe9f0e9---vesalesetafegotukupabiser.pdfIn PDF document text
    • https://rossbeede.com/userfiles/file/67173357497.pdfIn PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/tovesi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=como+descargar+crash+bandicoot+3+para+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_off0000d39e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD39E 18604 bytes
SHA-256: 1d7bc93f70231319e334643dc338ff147c202b6dd6238ef419d24d93fd5d8c51
font_01_sfnt_off0001041f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041F 11256 bytes
SHA-256: a4e86e2e2db1d3e317002b5ce0a9cd436c3c25bb3d1206fb28f41f69c2673720
font_02_sfnt_off00011df8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1