Malicious PDF — malware analysis report

Static analysis result for SHA-256 5df35426386b5ff9…

MALICIOUS

PDF

92.6 KB Created: 2021-09-14 22:51:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 78d1271e74b3469a2a4d5d0b1fc74c7f SHA-1: 1c9d311c4cf3295b0417c65115e90cf2c2d41307 SHA-256: 5df35426386b5ff954e684fcf1c0cfdd822ce94deb008b4b9fa84ff826875a25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external URLs, many of which are hosted on compromised WordPress sites or disposable domains. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9777

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://nomylo.ru/uplcv?utm_term=reverse+tethering+noroot+free
    • http://daiichihousing.net/uploads/news_file/kewegibizeripezaxul.pdf
    • http://palaciodelosnavas.com/userfiles/file/batulupibogiralaxu.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/86302928015.pdf
    • http://k-sta.kr/FileData/ckfinder/files/20210907_C72C1D73ED45468B.pdf
    • http://hulstcustoms.ru/uploads/files/jikemojisabopimojuzenija.pdf
    • http://michellenevinracing.com/FCKeditor/file/25408415670.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613c22b46bdf6---bakoloduj.pdf
    • http://studiobardinisrl.com/userfiles/files/28930565763.pdf
    • http://cuboni.com/uploadfile/hong202109102306182551.pdf
    • http://agedwedfjtj.pretty-match.com/upload/files/sugatopavedokipuvevo.pdf
    • http://medicalproduct.hu/images/files/48148257539.pdf
    • https://adminico.nl/userfiles/file/14342521306.pdf
    • https://rt-totaalafbouw.nl/userfiles/file/56242120585.pdf
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b6f875740---17007480354.pdf
    • https://digireg.dk/upload/dukupusebibefamurejej.pdf
    • http://bassbasement.org/userfiles/file/batawubelogivi.pdf
    • https://alquimia.in/admin/fckeditor/editorfile/77376283741.pdf
    • http://bivalyracing.hu/files/file/87026071718.pdf
    • https://rjpexport.com/files/nasuregavojesobibipo.pdf
    • https://isosklo.cz/uploads/xefegidowipi.pdf
    • http://www.immo-uno.com/ckfinder/userfiles/files/16904729838.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613719f3c8cb3---12097146196.pdf
    • https://middletonchambers.com/ckfinder/userfiles/files/3224022237.pdf
    • https://bosgo.mn/uploads/files/pokipugaditurev.pdf
    • http://jobsandhi.com/uploaded_files/userfiles/files/64389363147.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/3af148e86759f1c6f1b43d196386637a/vepamivuzisenibotoganir.pdf
    • http://behtarinekhodetbash.com/files/files/85361695624.pdf
    • https://ontech.vn/images/ckeditor/files/21100179279.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_off0000edbc.bin
d1c49061ebb44cf48d04722a6595a0829313cc7a212e15bd372db75236194436
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDBC 18144 bytes
font_01_sfnt_off00011d80.bin
da33af8296572adfce0a3170f6f99ba7c9e695fd7006619b0d2c3007a72e067f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D80 10396 bytes
font_02_sfnt_off00013500.bin
0e4cde3d5bdd5452960de995a4807c8da4ec665155a9812e2f8e54e6c49b7878
pdf-font-stream PDF embedded font (sfnt) at offset 0x13500 16448 bytes
font_03_sfnt_off00014bd9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14BD9 16792 bytes