Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cc40f1b6d4105eb…

MALICIOUS

PDF

70.4 KB Created: 2021-09-09 11:17:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fc0c04b7e760369d0dca801330f3795e SHA-1: 9ac02631293567ede0361811b8df08281c352a6d SHA-256: 4cc40f1b6d4105ebc9b0dd1587b25feeab0adcb65fad01ccbefc6d4843862416
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicating a link farm designed for redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The primary attack pattern observed is the use of a malicious document as an attachment in a phishing attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

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://opusincertum.it/userfiles/files/kuxarowimimunirekazupuxo.pdf
    • http://nj-rshb.com/v15/Upload/file/20219123189825.pdf
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/f668bdcdd0dd9a451104f3e8902c2574/24961748307.pdf
    • http://tnslib.su/userfiles/files/duzetotun.pdf
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/matuzunim.pdf
    • http://hyunshin.net/userfiles/file/mejanizogifutolirip.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161358eddeb347---novojibidegud.pdf
    • http://tortsurprise.ru/upload/redactor/files/regitabi.pdf
    • http://ettorebelfioreliutaio.it/userfiles/files/34183151645.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133794fdc8b4---81429615035.pdf
    • http://jonme.net/ckupload/files/mufetafokutix.pdf
    • http://www.naturhalles.fr/fckeditor/userfiles/file/6565131404.pdf
    • https://liepasmuiza.lv/userfiles/library/68259678566.pdf
    • http://aokunoil.com/ckfinder/userfiles/files/vumeboremerelobibe.pdf
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/40700574764.pdf
    • http://indemo.pl/Image/files/dugajajagebegozadu.pdf
    • https://jokerprod.net/userfiles/file/29407019223.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305f570ae91---91107183789.pdf
    • http://garmaclima.com/uploads/ckfinder/files/savuruxunapub.pdf
    • http://www.centralperdana.com/file/nujuzafiwofe.pdf
    • http://vucert.vn/uploads/files/20083455724.pdf
    • http://ytovietnam.net/ckfinder/userfiles/files/kivivezujukuwizelokaxuzek.pdf
    • https://bagstyle.uz/images/file/kevubipirixilarorubit.pdf
    • https://sergeca.com.ve/ckfinder/userfiles/files/88836842549.pdf
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/vasusitikifowunip.pdf
    • http://80tner.netsociality.com/upload/files/tosadalidava.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=overdrive+ninja+shadow
    • 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_off0000b4f6.bin
ac12cd6526a9db4c9d31c7c861e0a9423651377e8b63364c20afa894bbbd6123
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4F6 15888 bytes
font_01_sfnt_off0000dc61.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC61 16792 bytes
font_02_sfnt_off0000f478.bin
de4bd442e72ea2e8d4b7095cadddff02418cbbc25046e69dd4674dce8603b6eb
pdf-font-stream PDF embedded font (sfnt) at offset 0xF478 10508 bytes