Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8535801444be9a5…

MALICIOUS

PDF

74.8 KB Created: 2021-09-18 06:34:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cb04892ed2c92250b04982c83c402376 SHA-1: 0de70380206fb395298df9b316ad581b4e074659 SHA-256: a8535801444be9a54a9b8717dbaa7ec6cefa82a02d7b8a2e1fd8e478d85b4f46
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and ML classifiers, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. Embedded JavaScript streams are present, suggesting potential for further malicious actions like exploiting vulnerabilities or downloading additional payloads. The primary goal appears to be redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bfull.ru/uploads/files/58209161791.pdf
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/tenirabokenidetonol.pdf
    • https://tonerihned.cz/userfiles/file/jupakevutumedelafa.pdf
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/452970c3a89856e80cc10385f32dddbf/81913884325.pdf
    • https://fullgame.hu/uploads/files/15691348402.pdf
    • http://cimkezes.hu/uploads/ckfinder/userfiles/files/diwigirifoze.pdf
    • https://oasis-travel.ro/files/rerodotesajekopupamo.pdf
    • https://k85shj16h-561lt.com/contents/files/4456570380.pdf
    • http://kunjipsc.com/uploads/files/77115869818.pdf
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/161416a53591de---somutemadomatagidamosaw.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/161434e51d1087---gipedapapoliselaluraxano.pdf
    • http://blekinge.boj.se/uploads/userfiles/files/romakexetagexazinuvo.pdf
    • https://cargobull.cz/res/file/66420853421.pdf
    • http://daming-school.com/userfiles/file/77880866077.pdf
    • http://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/30346066354.pdf
    • https://shatalarab-llc.net/userfiles/files/lekif.pdf
    • http://msiutilities.biz/documents/15702040298.pdf
    • http://edumedcare.pl/upload/files/fevumevuroxubazita.pdf
    • http://eyupsifalibitkiler.com/resimler/files/17283467673.pdf
    • http://tucholainfo.pl/userfiles/file/94224482329.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf6ca81bee---72045323198.pdf
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ed35903d0---zegekes.pdf
    • https://kcss.hu/korosi/userfiles/file/15397536804.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/s9vse0v3vcvg1pit54ipj3ugp1/20293707170.pdf
    • http://rfaaa.com/UploadFile/file/20210917050913158.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=friday+night+funk+apk
    • 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_off0000ba9c.bin
dd931e986b6f27590f6b54b7bf459ed26abcc8cf0fd940eac1323e4886c43579
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA9C 19664 bytes
font_01_sfnt_off0000ed7b.bin
9de07494edb15ccb094260e2ff5b96123419508d7f5ab407e682616773fa6c6f
pdf-font-stream PDF embedded font (sfnt) at offset 0xED7B 10596 bytes
font_02_sfnt_off00010559.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10559 16792 bytes