Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a9007ed56cb643…

MALICIOUS

PDF

76.0 KB Created: 2021-09-18 11:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 367b52ce738cdda00b0e8020063333ae SHA-1: 0c8679e826930e188ac0b6f8c948a60a4e12dfa0 SHA-256: b3a9007ed56cb6435bfe2433b5120b4d3ba83da3a499389fbaf08f14d2005b25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to what appear to be compromised websites or disposable hosting, indicative of a link farm or SEO spamming operation. The presence of ClamAV detection and ML classification as malicious, along with heuristics flagging it as a link farm and pointing to compromised CMS uploads, strongly suggests malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://cructi.ru/uplcv?utm_term=telecharger+skype+gratuit+sur+android PDF link annotation
    • http://www.trisad.kz/ckfinder/userfiles/files/53860173611.pdfIn PDF document text
    • http://psycare-spb.com/userfiles/file/40931323387.pdfIn PDF document text
    • http://ylgems.com/file_media/file_image/file/88169036541.pdfIn PDF document text
    • https://ijp2.com/contents/files/sisonufun.pdfIn PDF document text
    • http://dichvutot99.com/webroot/img/files/bajikavikuwujimik.pdfIn PDF document text
    • https://comtraining.cl/userfiles/files/13083014480.pdfIn PDF document text
    • https://coluer.ir/documents/file/vebosexevibanobuniral.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/morovawedigigozakotajes.pdfIn PDF document text
    • http://pphjako.pl/userfiles/file/wovafuwaf.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161423976b7131---tijatopemejapoxu.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/fowosusomipu.pdfIn PDF document text
    • http://oodow.cn/upload/file/2109050155002133697s1ou1gj6ot5.pdfIn PDF document text
    • http://sourceit.ke/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/nusibibex.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d06cccdbc---memobakewikupijomazevij.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/nudarexepogitu.pdfIn PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/vesamukipizogevofosudabit.pdfIn PDF document text
    • http://robertwestlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83373337483.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ffaeed2cfe---83821923946.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109071558025261.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210905132059.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/vitepegewesekile.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/58824407652.pdfIn PDF document text
    • 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_off0000bf67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF67 19844 bytes
SHA-256: 796501496ee2dbba5492f9c056f529b04ee99f3c1d631fa73ba9852456bc0f58
font_01_sfnt_off0000f086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF086 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001089d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1089D 11064 bytes
SHA-256: 90be6975c19c2c5de37478db0d6b2b7f9943862ac81d9ba5e039caf8a43e9ee1