Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d1485ddb9e235b…

MALICIOUS

PDF

81.6 KB Created: 2021-09-07 12:58:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 64afa1684548471d358b2b1e38c6df89 SHA-1: cc709173bf9833d39d3caedd4b8c7de539fb97b7 SHA-256: 81d1485ddb9e235b87bd4685368549c1c25559e27856559738042add1909732c
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery via these links. No scripts were extracted, but the structure and URL analysis point to a common tactic of using compromised sites to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://shukokai-voves.fr/userfiles/file/fevepimabiburigutaxufijer.pdf In PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/vozogiwavodazulatuvug.pdfIn PDF document text
    • http://canavesiobruno-architetti.it/userfiles/files/tuviparugalar.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/a5635c4fcbbd0d90409c4bbda2e7b90b/79528433341.pdfIn PDF document text
    • http://ytovietnam.net/ckfinder/userfiles/files/54731086867.pdfIn PDF document text
    • https://legyenegyjonapod.hu/userfiles/files/51043228438.pdfIn PDF document text
    • http://cmtoolsrental.com/user_img/files/42013729173.pdfIn PDF document text
    • https://kingwrapcarspa.com/upload/files/repolovesinunolegukos.pdfIn PDF document text
    • http://coytex.net//ckfinder/userfiles/files/dafexiwigut.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160917cd41c512---desexosikuvofe.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/19209238377.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/15610097835.pdfIn PDF document text
    • http://classicalgardenornaments.com/uplds/file/vimolazaderidujimixopa.pdfIn PDF document text
    • http://businessvaluationapp.com//fck_files/file/fejovonolidumojufosabo.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/89576651271.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160bda48294ea9---xopifuwufolozuvubafeki.pdfIn PDF document text
    • http://regmac.net/userfiles/files/lifasegaxigajes.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/vonosasutajeledulameb.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/2hdjd2ofpcvoq3ql5hvv8e4h72/ligisafimedeze.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/zilimusosikumigejujevabiw.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/a06dbcd20817653ad09c5a93772ec4cc/badugono.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160710e178cd2b---83993557789.pdfIn PDF document text
    • http://nicolalazzarotto.com/userfiles/files/zokukuruza.pdfIn PDF document text
    • https://b2cexpressdemo.com/userfiles/file/labaxowajegobiw.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/002200da5a16a60b2230262bacd17b1d/zezavaxudaxibiwowasur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=terminating+and+non+terminating+decimals+worksheetsPDF 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_off0000d7ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BA 10956 bytes
SHA-256: 8820088a1ef5ecca462612a7c5112e2cd6f9dba44551e0c3c08bb5f00e0c5cc7
font_01_sfnt_off0000f0c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0C9 18196 bytes
SHA-256: 59deb9bd3b44371d308a8a9fbec24cc0333ec4ec66ac42d6c437e0673b762d61
font_02_sfnt_off00011ff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1