Malicious PDF — malware analysis report

Static analysis result for SHA-256 18bae137cfe97171…

MALICIOUS

PDF

87.5 KB Created: 2021-07-23 00:23:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a9c9a44164dd49ecf3ed047fd88822e SHA-1: 69fa193576e09ddee354aa7a684fd508dd9ece06 SHA-256: 18bae137cfe97171ff4bfffdf30112c1f4d1badddfc77e3cfdd7243d89f9dcf4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous links pointing to PDFs hosted on compromised WordPress sites, indicating a link farm designed to distribute malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly suggests a phishing or malware distribution campaign. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2ead6540a---babere.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085fd3abc027---78853837942.pdf
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/3p96g0srh4cqsgbq9cdke5lb97/28896692350.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160818513046d6---kewezivanojanovobunewim.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/dls88f01ub00nfomii2pskcac2/64394689829.pdf
    • https://akconta.com/uploads/files/xivemudolijitareveneja.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607502550a4f0---190341495.pdf
    • http://carsonpokebar.com/uploads/files/betokadabepowanoxor.pdf
    • http://chithanhplastics.com/uploads/userfiles/file/gutariwadojajewijiko.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160b054903524d---megogeruzor.pdf
    • http://karinameal.com/imgdish/files/7685364936.pdf
    • http://praxis-greve-polley.de/web/editor/files/rikonuzabesizuvonusanoj.pdf
    • http://steelbo.com/uploads/admins/u0/files/20210530103222.pdf
    • http://agiusfuneraldirectors.com/files/file/309236683.pdf
    • http://hyunbulsa.org/~ewedd2/userfiles/file/rexevegebepifobatag.pdf
    • http://xn----8sbosgn1al9i.xn--p1ai/ckfinder/userfiles/files/filonixanebenowiwozuzu.pdf
    • https://davidfoleyinc.com/userfiles/file/34543284053.pdf
    • http://pinzimoniofiumicino.eu/userfiles/files/10479641516.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077b430531f7---49700730465.pdf
    • http://rhoptik.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/nalovevimojexus.pdf
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d72e1941cc---40389560249.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/571820657c93f3d52eb093db7fd7711b/duxininulosoj.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c0087c296---71391084333.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=kvl+kcl+problems+with+solutions
    • 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_off0000eec8.bin
e9afc6752f4b8275c7f40730865634ad3d00c41c077d4c8725044b1956fd2e3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC8 10952 bytes
font_01_sfnt_off000107ce.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x107CE 16792 bytes
font_02_sfnt_off00011fe0.bin
c464fb11555141d5771c657d51f259df5af766c7ae33d7fc807a4445e1706ed0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FE0 17320 bytes