Malicious PDF — malware analysis report

Static analysis result for SHA-256 831f255b4d18571a…

MALICIOUS

PDF

82.6 KB Created: 2021-08-31 02:29:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3a4d607a25713b9f8691458e28d73d88 SHA-1: 946dec111364b5ccd9045cbed07c12bd61585018 SHA-256: 831f255b4d18571a15eb385f07cd70187936ab5a381db201b9a362af2c79491d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely responsible for redirecting the user to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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.
  • 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.
  • 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://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/928ca10d6558643f58ba26643b3d73bf/gobilowudenelenipuvote.pdf
    • https://wodepcb.cn/uploadfiles/files/98616958705.pdf
    • https://nsck-cykelmotion.dk/userfiles/file/pebipuxukubu.pdf
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/ruvidadixi.pdf
    • https://www.erenang.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e08624a71f---nugamuloxudobuguzaj.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160ccb1d5f21d8---94461124963.pdf
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/15065196220.pdf
    • http://onlineexpert.in/userfiles/file/26932013442.pdf
    • http://cichanski.com/Upload/file/movipadexudetupewazerut.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160749e911ad48---relefuketolipakegenajule.pdf
    • https://meganimal.pt/site/upload/file/16359865013.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be71996d9a7---gajagibe.pdf
    • http://inter-travel.hu/_user/file/71458687209.pdf
    • https://guijek.com/userfiles/file/gujatezumet.pdf
    • http://solac.nl/app/webroot/files/userfiles/files/39804035782.pdf
    • http://akkoryazilim.com/userfiles/file/84065633710.pdf
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160920b9a1d58a---10842876454.pdf
    • http://quanhoangtsi.com/upload/quangtri/files/68801790008.pdf
    • http://sincaremedicaltour.com/js/upload/mezutoxutowix.pdf
    • http://rorolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zidenezax.pdf
    • https://rcot.org/userfiles/file/bedenivar.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a13f3b255fa---dapeba.pdf
    • https://tsolisp.com/files/file/zedokevupapokaw.pdf
    • https://aduanaldelvalle.com/userfiles/file/75097416103.pdf
    • http://grafiport.com/userfiles/file/wuwuraviriviloruvinoz.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=grievous+bodily+harm+examples
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dcd7.bin
0b9cbc59503e9fcbff82476ad6b013ae502f229e651ec329bf0bfaec9874418e
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD7 17056 bytes
font_01_sfnt_off00010901.bin
a2b3360f103767de4b4bfac4c2afc0160be3b03e43c347bcd14588773f7bc923
pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 11016 bytes
font_02_sfnt_off00012274.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12274 16792 bytes