Malicious PDF — malware analysis report

Static analysis result for SHA-256 f77ff51320674d56…

MALICIOUS

PDF

77.6 KB Created: 2021-08-23 13:24:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 46f95c7f1e71282ec10a410958aaaa2a SHA-1: 4d90a82036761ff879ae11af4c69a39ef3bcd0a2 SHA-256: f77ff51320674d566cffd56ce1dd502ef7626b1aacb0d9de5fd7ccab6b9ec299
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains multiple links to external websites, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution attempt. The heuristic firings indicate a link farm strategy, likely to obscure the true malicious destination. ClamAV detection and ML classification confirm the malicious nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6556

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://cructi.ru/uplcv?utm_term=safety+and+health+in+construction+pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610817047766b---jipugagujijaxagex.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079382f34953---2261445632.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ca83cc56a5---feteri.pdf
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/51c1597cab8ff86342359a59c6fca70f/nebenipifovodexiga.pdf
    • http://adamlegal.com/userfiles/file/85656495235.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/4no33jsd7e2mak3f05sopqs5ql/gugobizibazakogasa.pdf
    • http://www.nbc.com.vn/ckfinder/userfiles/files/sikadufejoxafexurumodo.pdf
    • http://djpress.pl/Image/files/wapijusisoduxaxademejig.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/6750d242e130a6101a718604cacbed71/39290014812.pdf
    • http://x04ydivan.ru/userfiles/file/85555416619.pdf
    • http://voijin.com/userfiles/files/15217322921.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1611438ef10596---53385791040.pdf
    • http://dragoniresorts.com/userfiles/17881305387.pdf
    • http://metall-press.ru/files/3210800702.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b26b9d03b---bogudavexebefixuguraduv.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16077646ef4235---bofepigaram.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1610b0e44894cb---jotesaj.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160e834b114fa8---64415262700.pdf
    • https://2-view.org/home/view/public_html/ckfinder/userfiles/files/nakujesipuluzewuvepe.pdf
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/puojt46dct7ukadge2agk7neuc/81091063134.pdf
    • http://tugrabilgisayar.net/resimler/files/50038428196.pdf
    • https://gbagencement.fr/uploads/file/48639747709.pdf
    • http://agriturismocorteerbatici.it/userfiles/files/devikegebedigatawezig.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/k1t5qto053avdj1k61q72t1jg4/mukadabit.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607304473674a---76373407730.pdf
    • 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_off0000da82.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA82 16792 bytes
font_01_sfnt_off0000f299.bin
2299df94049b3ebaebf6970df61b47487eb5a1290d02fdd7284578ccaef72366
pdf-font-stream PDF embedded font (sfnt) at offset 0xF299 11004 bytes
font_02_sfnt_off00010c18.bin
50072035c679828c2488ced57dd46051a477359202056686b680c61a3fce589d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C18 16836 bytes