Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4dac3fe17fcbdd0…

MALICIOUS

PDF

71.7 KB Created: 2021-09-30 19:52:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dd3d147a8cf06c8499038ff068616189 SHA-1: 93e8d8fe26b51f7576b321ef0189ca8a0ea954b6 SHA-256: d4dac3fe17fcbdd0259e6e6da3b15354b1cfe1a7956236742ac1261aa6e1f67e
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier as malicious. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution campaign. The PDF itself appears to be generated by wkhtmltopdf, and the embedded content is heavily obfuscated, preventing detailed analysis of its specific actions beyond linking to external resources.

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://crewmak.ru/uplcv?utm_term=rick+steins+fish+gratin
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/758532fd071920ee72ae766aa84cdde2/27897099901.pdf
    • http://www.cda.org.hk/ckfinder/userfiles/files/34026509384.pdf
    • http://compow.net/ckfinder/userfiles/files/jewenesani.pdf
    • http://orthopediedelft.eu/files/kobugurununolutuxofu.pdf
    • http://strandedtattoo.com/file/zurifaxurepasozinevixu.pdf
    • http://yameitecl.com/ckfinder/userfiles/files/20210924_221619.pdf
    • http://zhouzhuanx.com/v15/Upload/file/202192869438824.pdf
    • https://aihr-iadh.org/uploads/FCK_files/file/namimasededemadowenases.pdf
    • http://debnine.net/UserFiles/File/xixigowopasop.pdf
    • https://webmedcentralplus.com/userfiles/file/30552996426.pdf
    • https://zhongzing.com/uploads/files/202109062200002415.pdf
    • http://alarm.pl/userfiles/file/3334002561.pdf
    • http://marcelponjee.nl/ponjeefiles/file/gexagupa.pdf
    • http://camdohungdung.com/upload/files/47517734759.pdf
    • https://poganyvolgyi.hu/userfiles/file/22733731801.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/56762d78d59002bb13f2ed6bc9ffa459/dedorilifukamosutuzalesun.pdf
    • https://kiofruits.com/admin/uploads/files/788394388.pdf
    • http://www.tivafa.hu/upload/file/wenuwinomijedelupax.pdf
    • https://parc-hotel.info/file/37062079234.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613097d5ccc97---baratinipapenoduvipob.pdf
    • https://hiperaktivite.info/userfiles/files/44099094218.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16155c90b6ed08---1138670430.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/u59c8fhepgdpe00nbp3r49dfb3/kuruxujometap.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371e11abd91---70859978639.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_off0000b4e1.bin
29c6515a9e9958bd8012b6d1729bbcc7c4fc2ae2e5b7e5102e67b5c43815e3d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E1 10584 bytes
font_01_sfnt_off0000cd02.bin
f4cac7bdeab2ead0dce3ee7407887de4c395285239c5faa1092e586526126b78
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD02 16844 bytes
font_02_sfnt_off0000f772.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF772 16792 bytes