Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51c2d2eb9a1956d…

MALICIOUS

PDF

81.8 KB Created: 2021-09-12 04:52:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a44bae1c37178ead352e684373f9ff4b SHA-1: 546a4c35caa7ac2a87dfb8a7da09b5e591b63649 SHA-256: b51c2d2eb9a1956d795c8bcc23c78548011db2428d4377467f53a568d04c0fbe
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious content. The 'SE_CALLBACK_LURE' heuristic specifically points to a callback phishing or tech-support scam pattern, where the document likely prompts the user to call a phone number. The presence of numerous embedded URLs, many pointing to suspicious domains, further supports the malicious intent, likely to host further stages or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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 http://nokianhakkablue.ru/ckfinder/userfiles/files/57016041259.pdf In PDF document text
    • http://www.casasemio.com.br/ckfinder/userfiles/files/buzuwowite.pdfIn PDF document text
    • http://thanhcongtechtra.com/upload/files/zafuzepexa.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202109090609562548.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/mibaturo.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/67850856386.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/49111071500.pdfIn PDF document text
    • https://altstudio.be/app/webroot/uploads/file/29749865247.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16139607b2d77c---66021768481.pdfIn PDF document text
    • http://feuerwehr-mittenwalde.de/mediathek/files/gunorutavafutavevinaraku.pdfIn PDF document text
    • http://youandisagenix.com/ckfinder/userfiles/files/38170211101.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/53730471345.pdfIn PDF document text
    • http://bestpokeya.com/uploads/files/92321794059.pdfIn PDF document text
    • http://vkp.ru/upload/global/file/zagin.pdfIn PDF document text
    • http://retailcop.ca/files/81815430452.pdfIn PDF document text
    • http://chrislahoda.ca/userfiles/file/33351567617.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/bugorenilosalivagenodu.pdfIn PDF document text
    • https://airin.lv/images/userfiles/file/bimom.pdfIn PDF document text
    • http://avvolodin.ru/upload/file/vowet.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/56117935497.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/sefejoxe.pdfIn PDF document text
    • http://daydeothe.vn/rich_editor/file/49145282239.pdfIn PDF document text
    • http://hwayoung.kr/upfile/files/sifunatagekururugowug.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/86369279234.pdfIn PDF document text
    • https://dobre-akce.cz/media/files/file/pafedipopoziw.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/rivipiwufovuzizoxit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=i+cant+download+on+playstorePDF 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_off0000db6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6C 10568 bytes
SHA-256: ec6296ecbe9f0fd85958526e978e76b0723983b98fd3174f755da4ccc6f2837d
font_01_sfnt_off0000f3c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C9 17584 bytes
SHA-256: 6072e7e2b8401d71f92fa3fb2da17eb93e8430882e5aa030be058a962b31e95e
font_02_sfnt_off00012119.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12119 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1