Malicious PDF — malware analysis report

Static analysis result for SHA-256 90ceb80955ec44ba…

MALICIOUS

PDF

77.6 KB Created: 2021-09-09 19:12:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1a5a5a7a5c423504275795d7aec81623 SHA-1: a62ad910238d1056d7c752162bf4ef5b25f84f5b SHA-256: 90ceb80955ec44ba40cfd24db4471a0d0910595ffcb1f614b8cb44be45e9fcfb
146 Risk Score

Malware Insights

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

The PDF contains numerous embedded URIs, many of which point to disposable domains and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights the nature of the links, suggesting a tactic to obscure malicious destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://tochuchoinghi.org/files/29622299280.pdf In PDF document text
    • https://sheenabusesandcoaches.com/userfiles/file/98333661788.pdfIn PDF document text
    • http://ekvatorbl.com/userfiles/file/filesekawopererifu.pdfIn PDF document text
    • http://prime42.ru/userfiles/files/lerugepifefopusin.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/fepixupodakifunamiveli.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/88439304101.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/sunikubazofivotumunurujex.pdfIn PDF document text
    • https://paklya.su/design/img/upload/file/janosazitozo.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/zizopapaxew.pdfIn PDF document text
    • https://greenvalleykerala.com/ckfinder/userfiles/files/68845658634.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613240bab8863---82500245318.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-5/20210905060019692053.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///2021091004831_287084863.pdfIn PDF document text
    • http://185.33.116.145/~acus01/upload/files/wakikopeg.pdfPDF link annotation
    • https://pharma-tools.pl/galeria/file/83012993423.pdfIn PDF document text
    • http://suamanhinhlcd.net/userfiles/file/71250721333.pdfIn PDF document text
    • http://www.vnv.nu/admin/library/ckfinder/userfiles/files/82389764604.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311f55703fe---zebolap.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/dojafuvojotumejitukagepu.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/65590186730.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/wexixadepanesaw.pdfIn PDF document text
    • http://handgun.ee/media/file/babovotuzeva.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/fepumibi.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/zupogufavu.pdfIn PDF document text
    • http://cuacuonnhanh.vn/Images_upload/files/97697378789.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/40383867115.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=free+ui+kit+for+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_off0000ce07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE07 10304 bytes
SHA-256: b842375df40a32d7552958275b1edcb008918f7f614827d575ed518e0e6ee5c1
font_01_sfnt_off0000e558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE558 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD6A 17056 bytes
SHA-256: 4f896c31eed67e4277eb43a23aff50d2178c0249d24d67b71503869ea6b54eee