Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a75116521f90ded…

MALICIOUS

PDF

73.6 KB Created: 2021-09-20 20:16:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4481bd184118932b3f840689f37e5512 SHA-1: d24c5c928594bc51b7af6770a5251378fb019134 SHA-256: 4a75116521f90ded5977d8a6b1e683d5ae74f098f8a4c69d239f4e7bef0a3742
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • 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://afslab.asia/upload/files/98358827315.pdf
    • http://111-orte.de/testarea/cwsCMSlight/media/files/14482006823.pdf
    • http://dancephoto.ru/userfiles/files/wipejariwojufetu.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612fbc0aa43ab---bujib.pdf
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/23106720607.pdf
    • http://devitohomesorlando.com/userfiles/files/fukufiwosixer.pdf
    • http://groupementpecheduloir.com/ckfinder/userfiles/files/99594151968.pdf
    • http://gloria-eurex.com/images/blog/file/70205954956.pdf
    • http://unixsensor.com/uploads/files/202109021347004601.pdf
    • http://centronegozi.com/public/rumorunirejijerabosal.pdf
    • http://modellszerviz.hu/userfiles/file/288281421.pdf
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles/files/sotomeri.pdf
    • https://sindonis.com/userfiles/file/vebosetofaka.pdf
    • https://dbhattacharjee.com/ckfinder/userfiles/files/16508547127.pdf
    • http://svb-volleyball.de/userfiles/file/ravutol.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613abb3d301c3---nadenaf.pdf
    • http://makassitools.com/userfiles/file///fadosebowipa.pdf
    • http://optimaglobal.net/ckupload/files/ziboxizavaguwagigamedu.pdf
    • https://andhimazhai.com/images/files/zawixu.pdf
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/161351278522bb---davakanoparud.pdf
    • https://keluargamimpi.com/contents/files/72733140556.pdf
    • http://morard-mcf.fr/data/Files/38880407398.pdf
    • https://www.highettmetal.com.au/application/third_party/ckfinder/userfiles/files/69425900622.pdf
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/jevagex.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=app+for+a1+smartwatch
    • 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_off0000bd1e.bin
e9610eaef608f03ab9cafc03c4ebee2d5fdd1145f91a5bae89dc210913d6164e
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD1E 16876 bytes
font_01_sfnt_off0000e8db.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8DB 16792 bytes
font_02_sfnt_off000100f2.bin
1db7947a581fa3c7b5f50657cdeb3be2e76cfc10214c3b8db05febf95ed5d4b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x100F2 10488 bytes