Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad824a38c1ce8d22…

MALICIOUS

PDF

87.1 KB Created: 2021-09-15 13:24:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 673b503122b6b73c335ffaec8a31aeb3 SHA-1: 48931829af44358c809054fee7736da0de194348 SHA-256: ad824a38c1ce8d22a12471ca16c4e9cfb53639ab76d4353d3b927039374e019d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm on disposable hosting, suggesting an attempt to lure users to external sites. While no scripts were directly extracted, the nature of the embedded URLs and the heuristic firings strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://huntic.ru/uplcv?utm_term=top+tv+latest+version+apk
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/24339276995.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140bc0523176---57947370864.pdf
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/33ecb92e62ce2ead75ac8ca6450a7743/75597810908.pdf
    • http://www.frank-diagn.hu/userfiles/files/fowikew.pdf
    • http://progettogeometra.it/userfiles/files/93144291252.pdf
    • https://permargi.com/files/galeria/files/rodotaboguxakagaxo.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614079048af7f---sisup.pdf
    • https://poganyvolgyi.hu/userfiles/file/wodopojajugagobojubikanix.pdf
    • https://al-wesam.com/userfiles/files/wegerowiferoxizixeme.pdf
    • https://mk-promotions.com/ckfinder/userfiles/files/14925412672.pdf
    • http://secondhandgraphics.com/usrfiles/file/zuvekenironudona.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138c50552669---jebomiseziponixav.pdf
    • http://gruaszarate.com/ckfinder/userfiles/files/97498393640.pdf
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/50461565693.pdf
    • http://samtle.net/ckupload/files/lulamafafilimanafefolev.pdf
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/lasoretuzonuzomodem.pdf
    • http://www.naturhalles.fr/fckeditor/userfiles/file/3927832735.pdf
    • https://hsse.hssanesteban.cl/files/dubudugafexej.pdf
    • https://linhngapt.vn/upload/files/kisutidupoxegor.pdf
    • http://unityproductions.com/upload/files/41820760566.pdf
    • http://ngocphuocjsc.com/public/default/ckeditor/files/vadujugoxudir.pdf
    • https://radekslodkiewicz.pl/files/file/wufisameretudiv.pdf
    • http://tnslib.su/userfiles/files/95587907748.pdf
    • https://ans5680.preneed91.com/upload/files/lidur.pdf
    • https://mtmhomeschool4art.com/mycms/uploadedimages/editorUploadedImages/file/xuxenugajo.pdf
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e119.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE119 16792 bytes
font_01_sfnt_off0000f930.bin
e0009c6466d71c8c72318281d16ac6566490ea646f2edd8d8afd8d36b161144a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF930 10364 bytes
font_02_sfnt_off000110c4.bin
bf553bb34523abad57e0e30594bf7e82d75f0262282c7b59a7ab88dda3f6d9dd
pdf-font-stream PDF embedded font (sfnt) at offset 0x110C4 20400 bytes
font_03_sfnt_off000144fe.bin
6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x144FE 1680 bytes