Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8865fabfd1191e0…

MALICIOUS

PDF

83.8 KB Created: 2021-09-14 01:32:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d6d7d34ba2a097e151a8d86331a6c1f2 SHA-1: b6964749dd1863d6bbcb024a7a34bd21d9b3522e SHA-256: b8865fabfd1191e0537a6f469166ee1a571392f7a3470b76162865cbba4e72cb
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using non-clustered links on disposable hosting, suggesting an attempt to obscure the true malicious destination. The presence of multiple external URIs and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://catamma.ru/uplcv?utm_term=modded+mini+militia PDF link annotation
    • http://nsfeed.com/_UploadFile/Images/file/bitunisoseso.pdfIn PDF document text
    • http://888chji.com/userfiles/files/dupirapodozavoziju.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///40092884859.pdfIn PDF document text
    • http://www.smartusb.info/images/library/File/guxokij.pdfIn PDF document text
    • http://jonme.net/ckupload/files/56384411163.pdfIn PDF document text
    • https://eijo.in/ckfinder/userfiles/files/wezepitej.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/47018256509.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/xegekozekukitebo.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613013146d20c---7597140543.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/ruxiwabi.pdfIn PDF document text
    • http://saigonradio.com/userfiles/file/xukuzelagobuvibu.pdfIn PDF document text
    • http://rtm-plus.ru/ckfinder/userfiles/files/kuzumewolinet.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138713119847---vesivokowejat.pdfIn PDF document text
    • https://mosallaesf.ir/uploads/ck/files/80819753338.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/91150183847.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcb895414c---44241056110.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/a35f960f4794455f01e9980f29708dcd/dezuteginoruwixufiw.pdfIn PDF document text
    • https://actionsporting.com/userfiles/files/12378743345.pdfIn PDF document text
    • http://jsdarvin.com/files/jikabiritiparogavirubek.pdfIn PDF document text
    • http://irths.com/upload_files/files/vuwozavabimurodegud.pdfIn PDF document text
    • http://raffaelecavazzoni.com/userfiles/files/71477167386.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/67476435171.pdfIn PDF document text
    • http://iswii.net/ckfinder/userfiles/files/79095357733.pdfIn PDF document text
    • http://vsrru.ru/userfiles/file/83332026048.pdfIn PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/figaxosof.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_off0000e58c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58C 10136 bytes
SHA-256: f6936a4c61b9626efdb227f9c4a2cfa8de81653a8fc3134f277abe896b3c5eaa
font_01_sfnt_off0000fc17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC17 18244 bytes
SHA-256: 5b2f1be7989a3834b747c804a50cd7c2b0e667981efcf35ee2de196b00598899
font_02_sfnt_off000129ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1