Malicious PDF — malware analysis report

Static analysis result for SHA-256 51e77768ab9d9a8f…

MALICIOUS

PDF

68.6 KB Created: 2021-10-01 10:01:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: dea334d00b55fd66f4cb2776bf7c9025 SHA-1: 6ce144376b43627f2235bb1567cef6516fb798fe SHA-256: 51e77768ab9d9a8fc9ecd8ac506619dca113afe367cd66df1d4561f14a21ee4d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm hosted on disposable domains. The PDF contains numerous embedded URLs, including one pointing to 'drafthe.ru', which likely serves as a redirector to malicious content. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest an attempt to direct users to phishing or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://drafthe.ru/uplcv?utm_term=turning+on+emergency+alerts+android PDF link annotation
    • http://zdrowejaja.com/Upload/file/6260076348.pdfIn PDF document text
    • http://unityproductions.com/upload/files/13785318929.pdfIn PDF document text
    • http://ambulanceservice.pl/userfiles/file/67662937488.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/79097111433.pdfIn PDF document text
    • http://agilesolutions.in/uploads/60557155768.pdfIn PDF document text
    • https://sinarwaja.com/account/files/sulukijusepuxumopitije.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/vebagilalogefoletatu.pdfIn PDF document text
    • https://rajatotogroup1.com/contents/files/sozijuribufezaro.pdfIn PDF document text
    • http://tko.wavedev.net/img/files/files/kulituliwusawutokuworirow.pdfIn PDF document text
    • http://derp74.fooden.com/UserFiles/files/35352423576.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/13856248791.pdfIn PDF document text
    • http://cabanagarden.hu/editor_up/subixuj.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/31208742760.pdfIn PDF document text
    • http://kubak-ubezpieczenia.pl/userfiles/file/44499450636.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/fuxuvutegafoja.pdfIn PDF document text
    • http://pivotal-technologies.com/userfiles/file/13069903440.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/80710731406.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161305309323d5---vopuxeliduju.pdfIn PDF document text
    • http://majstrissmt.eu/www-data/file/sikuva.pdfIn PDF document text
    • http://cana.vn/uploads/userfiles/file/57078391545.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/26301065810.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/vowifitomedovinezeniji.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342b114e1d1---diruwatiripemosowu.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/kotibefar.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/kegerorusepesutalu.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_off0000b02f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB02F 10892 bytes
SHA-256: d372fd3e2cb4cab696f20897cc89f731bc3bfb6b3cd6b9dbf63a60b7aa8b2c9a
font_01_sfnt_off0000c92d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC92D 14176 bytes
SHA-256: 3df1c70c0090d69583a2779059fa30bee16160e11708d3f211c5454baab57639
font_02_sfnt_off0000ecbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1