Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb5a088fbf2dc88d…

MALICIOUS

PDF

79.7 KB Created: 2021-09-08 19:21:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 42b8fb5a939570c57d68b32729ef1218 SHA-1: 4787b9cedbde17c9777e2d944d0f57d392d7da01 SHA-256: bb5a088fbf2dc88d9b4ee862340be80e54f9039389c506724f7611784fe8c3aa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Notably, some links point to compromised WordPress upload storage, suggesting a potential distribution point for further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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://razredna-nastava.net/files/85082494165.pdf
    • http://kayamedbursa.com/userfiles/file/72567298618.pdf
    • http://k-sta.kr/FileData/ckfinder/files/20210908_0081FCA667E298D9.pdf
    • http://szao-spb.ru/images/news/file/zotenedeja.pdf
    • http://www.sun-green.eu/ckfinder/userfiles/files/9131173639.pdf
    • http://thevalleytrader.com/files/morogefosusuvovikizev.pdf
    • http://dolphinegypt.net/userfiles/file/pifutumibuzagilomamu.pdf
    • https://girilawfirm.com/content_files/files/51950529584.pdf
    • http://boekenwinkelindex.nl/images/uploads/xoromokib.pdf
    • https://biocoils.com/img/file/tidejuladowesewoketug.pdf
    • https://tasivn.com/upload/ck/files/pijaxexa.pdf
    • https://sandipkumardutta.com/ckfinder/userfiles/files/nesiji.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161377181652c9---rijaselareda.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a9bc5b107---92005923516.pdf
    • http://kovacsoltvaskerites.hu/images/file/66175252331.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613882e01a4ac---taxonejebowagag.pdf
    • https://aarhuskortet.dk/images/file/54472042025.pdf
    • http://eco-versute.com/app/webroot/ckfinder/userfiles/files/1069019650.pdf
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/xelikasif.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/6b2b318741e4cbd1ebd96cb1d9515470/86629137514.pdf
    • http://piri-piri.pl/ckfinder/userfiles/files/25860248843.pdf
    • http://chemonova.com/FCKeditor/file/xufegesafalitijev.pdf
    • http://weforyou.it/userfiles/files/69229475074.pdf
    • http://reginahajo.hu/_user/file/pewavexitonatinugu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=dell+3620+workstation+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_off0000cf6c.bin
9f591baf8c27140669b85e5ff228265552aebcb75649ae31ecd6d3cbc990d517
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF6C 11252 bytes
font_01_sfnt_off0000ea16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA16 16792 bytes
font_02_sfnt_off00010228.bin
c3af51b7060450035a2cb4a51794a6bb55f9ef2c2027f066a011ea98d88b4312
pdf-font-stream PDF embedded font (sfnt) at offset 0x10228 17760 bytes