Malicious PDF — malware analysis report

Static analysis result for SHA-256 5da6de791c45e059…

MALICIOUS

PDF

80.5 KB Created: 2021-09-10 00:05:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ff37cb5377dbe9f8024134ffb2fad888 SHA-1: 61ed56f7767047eda7fcf634f9443087c4fa4494 SHA-256: 5da6de791c45e059047af2810a6c37c2075bd337f201bfdb9d593faff4a86fb7
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to obfuscate the malicious links or perform further actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://bczenekar.hu/files/file/24059287488.pdf In PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/logajokalubiwedifabi.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/mijelikikateserote.pdfIn PDF document text
    • http://trieuduong.com/images/Download/laxiti.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/vozirifikutefononuvugunan.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/jibodirutedofalezekizo.pdfIn PDF document text
    • http://mastervin.ru/files/file/pilunosete.pdfIn PDF document text
    • http://azinsaghf.com/cache/fck_files/file/semijimuruxaf.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/galudopojilupukok.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/rafilewefuziziforiweri.pdfIn PDF document text
    • http://ssss-sangam.com/userfiles/file/14686734596.pdfIn PDF document text
    • http://pappteam.hu/userfiles/file/88372246754.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/5lmlqup3pho593mli5u7mi9ip4/57742943679.pdfIn PDF document text
    • http://fonnepal.org/userfiles/file/64543661775.pdfIn PDF document text
    • https://rivieresoceanie.com/userfiles/file/21055495772.pdfIn PDF document text
    • http://gamboeng.com/assets/ckfinder/userfiles/files/87375138986.pdfIn PDF document text
    • http://pitin-akutsu.com/js/upload/files/47989102528.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///bewupebekufakifi.pdfIn PDF document text
    • https://hazeloyun.com/calisma2/files/uploads/33493374625.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/87813579706.pdfIn PDF document text
    • https://gkscam.com/userfiles/file/38262579529.pdfIn PDF document text
    • https://lingchuanfloor.com/app/webroot/userfiles/files/vepijabojobenupalud.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a76e12ca05---53112328709.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=latest+processor+in+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_off0000d81e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD81E 10420 bytes
SHA-256: ca927b43e35ebbde33e2660acc210caf92470593ca577fb6e9ddc66da99572f1
font_01_sfnt_off0000efd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD2 17336 bytes
SHA-256: 6a0a3b7f9c7665fc0ed71afe6f6455322c5f0b405b1dc75c4c0e297211257436
font_02_sfnt_off00011c87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1