Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38e3ac7a8bc048a…

MALICIOUS

PDF

80.0 KB Created: 2021-09-09 02:26:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 23dbea24c231e34963e669d3b94d592a SHA-1: 94be102d5226fb39103857dd966ee5d6988d8aeb SHA-256: a38e3ac7a8bc048adcd2db9b3a90a09b5dc72331b8ece96e03948e62c64d7621
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs, many of which are hosted on compromised CMS platforms or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support the attack pattern of luring users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://chcial.ru/uplcv?utm_term=the+screwtape+letters+pdf+free+download
    • https://nbtele.com/en/cache/fck_files/file/6899155377.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161321eee41ab9---vexuwupuguduvujepe.pdf
    • http://deccanquest.com/konadnew/userfiles/file/nodosozelegutani.pdf
    • http://terredellamagnagrecia.com/userfiles/files/56066246681.pdf
    • http://usateatop.com/_upload/files/90353340486.pdf
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613074b01091e---12498554435.pdf
    • http://candientushinko.com/images/file/12429086431.pdf
    • http://tomasmrazek.cz/userfiles/file/jolazesoz.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/ebcfd12eb8d6f3b40b8ea22c3dfbea8a/83895766831.pdf
    • http://studiozammuner.eu/userfiles/files/verababupavux.pdf
    • http://leasingtowers.com/ckfinder/userfiles/files/rafaxod.pdf
    • https://heks-tech.com/app/webroot/userfiles/files/dovivegovagitunonogobip.pdf
    • http://fobosgrunt.ru/files/ckfinder/files/56242140368.pdf
    • http://biznesfishki.ru/files/userfiles/files/koladegipidimanaj.pdf
    • http://koutingchina.com/upload/files/mobizojediwiget.pdf
    • http://amirafouad.com/uploaded_files/file/93300724750.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f6cb3c3cc---72759305384.pdf
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/71594057025.pdf
    • http://holdemigny.fr/ckfinder/userfiles/files/72283431307.pdf
    • http://brmxn.com/userfiles/file/20210902064418_zpb0lm.pdf
    • http://stilistspb.online/public/files/uploads/files/kufenep.pdf
    • http://meijialx.com/ckfinder/userfiles/files/84898649855.pdf
    • http://wpchkg.com/upload/image/file/58574444797.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d204.bin
44acb99d5fb2e3e1a39da19146ab4920bc1c2b8ead52cd4cf6f7ee19430e28e4
pdf-font-stream PDF embedded font (sfnt) at offset 0xD204 10672 bytes
font_01_sfnt_off0000ea8c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA8C 16792 bytes
font_02_sfnt_off0001029e.bin
407e581d59a99e6af0cff930df94b084f470248b091b1e56f1dc7f9940c30e71
pdf-font-stream PDF embedded font (sfnt) at offset 0x1029E 18308 bytes