Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b6b3ec5ff9fd5b…

MALICIOUS

PDF

70.5 KB Created: 2021-09-11 16:27:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dbf902c25154bd16be92fa717055657b SHA-1: c7d076acd37a7c2416dcea24700038ca31945248 SHA-256: b4b6b3ec5ff9fd5bfa7582a69a369133568b851c404e69eb06bf231be371ddc7
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure indicate an attempt to exploit users through deceptive content.

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 https://cuatudongsaigon.vn/uploads/files/zokitisodezeti.pdf In PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613195dbcc16c---41014260803.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/lolexadefanofora.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/muwovodivazitubemeraj.pdfIn PDF document text
    • http://coolbiotech.com/upload/files/10129046411.pdfIn PDF document text
    • http://baheth24cars.com/ckfinder/userfiles/files/nevezolevup.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210903122122.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/68101684126.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/wemaritadikubeluvo.pdfIn PDF document text
    • http://mestan.by/images/file/wovix.pdfIn PDF document text
    • https://alemarferries.alemarsnp.gr/ckfinder/userfiles/files/bamanapedikudepux.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613959e448066---bazazivaka.pdfIn PDF document text
    • https://cubic.is/userfiles/file/debigujawumatipimomix.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/de0d743e6325cbe898c75c8fb4a251cc/75857174074.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/284106160.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/64668689210.pdfIn PDF document text
    • https://tradegateindia.com/userfiles/file/jomaxovedetifafiv.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/20341507852.pdfIn PDF document text
    • http://metabolizmusonline.hu/images/upload/file/24922725891.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/bepopimexizesasulifalu.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/26521473674.pdfIn PDF document text
    • http://transportdiverse.com/uploads/files/42939787453.pdfIn PDF document text
    • http://elskenecologie.nl/files/18493815661.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/gotawixikomujanidexow.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/42769385621.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=25+free+spins+no+deposit+casino+australiaPDF 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_off0000b632.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB632 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE49 10872 bytes
SHA-256: b5ed857379ee00b08571cde2bf4c3b548e9e1600bf8384fd4c4c6c056c28e33f
font_02_sfnt_off0000e78c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78C 14616 bytes
SHA-256: 3844cfbde578e06e0fcdc18145191ab7673cbe7f20f057bed2e0e0de337dd509