Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8dca61e2a57d976…

MALICIOUS

PDF

68.4 KB Created: 2021-09-16 05:43:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 029e0a51b1570b3ccc02f1c7d2ee1197 SHA-1: 06c4bbca0ee7977f482e3944fdb66be69e31ba21 SHA-256: b8dca61e2a57d976f0c28ce0b13afc02458c715221696b4bb5ba70fb87f94e0f
182 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external URIs, indicating malicious intent. The heuristics strongly suggest a remote support lure combined with a link farm, aiming to trick the user into downloading a payload. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://minjar.mebel18.com/uploads/files/ketipirewo.pdf In PDF document text
    • http://mkpstroitel.ru/upload/files/37951676443.pdfIn PDF document text
    • http://jjkxmy.com/upload/files/202109131948539451.pdfIn PDF document text
    • http://bitree.net/ckfinder/userfiles/files/misexutokud.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/161423d5e08703---vupere.pdfIn PDF document text
    • https://kuzeyilac.com/resimler/files/39339654571.pdfIn PDF document text
    • https://xn--z4qq44i.tw/upload/actfiles/sokekikuwunijuzanusimosu.pdfIn PDF document text
    • https://quasar.mago.ro/ckfinder/userfiles/files/kefugepuxeduvezi.pdfIn PDF document text
    • https://petribax.com/userfiles/file/zigisebefuvovalit.pdfIn PDF document text
    • https://vinaconexmec.vn/uploads/news_file/gotivap.pdfIn PDF document text
    • http://ottuk-e.org/userData/board/file/talusokujuwuwesoji.pdfIn PDF document text
    • http://greathorserider.com/ckfinder/userfiles/files/93380221175.pdfIn PDF document text
    • http://galsabino.it/userfiles/files/dodemi.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/fonuzowad.pdfIn PDF document text
    • http://myagreement.com/UserFiles/file/88047583508.pdfIn PDF document text
    • https://cbconsulting112.ca/userfiles/files/vosulapukezesejufok.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/j3b1lak20q3upb3sct4vsk97r0/laxojabelijilodilovevusap.pdfIn PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/bufejupararojaxerupine.pdfIn PDF document text
    • http://pravkniga.ru/files/userfiles/files/26764570759.pdfIn PDF document text
    • https://itscebu.com/upload/file/20210914195048.pdfIn PDF document text
    • http://starma.pl/files/file/juputis.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/77385936455.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/66647268033.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=autocom+cdp%2B+apkPDF 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_off0000af53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF53 15228 bytes
SHA-256: 579a962142f216c412892ca43273245d1dd7b3465c1a03469100a20279fd20aa
font_01_sfnt_off0000d589.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD589 10208 bytes
SHA-256: 21439524d4223680c399b7d4d866e40650fdfee0e234d99e5f0207a6a623e625
font_02_sfnt_off0000ec85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1