Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbbf359a6118e880…

MALICIOUS

PDF

72.3 KB Created: 2021-09-09 21:20:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91db056ddac6925300728ec9db009667 SHA-1: 530bac5e46fc77d95225ffd1433bb4eebb6b8599 SHA-256: cbbf359a6118e880d9ff41f2771ae57711673459550d641c01e9dd87521bb25b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://catamma.ru/uplcv?utm_term=example+of+soft+real+time+operating+system
    • http://snieznik.pl/userfiles/file/17622480886.pdf
    • http://panziofabian.hu/fck_kepek/71816233599.pdf
    • http://cowmoo.org/ckfinder/userfiles/files/womimiwepir.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612efd47ddeb8---vazumuvonunokatokelamoxob.pdf
    • https://superpackeg.com/userfiles/file/46833458003.pdf
    • http://unewstoday.com/task/userimages/file/25197300468.pdf
    • http://sh-songshi.com/admin/upimg/file///neguzezubeposawukonogulan.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0261420ed---83736227567.pdf
    • https://cukimentescukraszda.hu/files/files/31180751957.pdf
    • http://dirpub.org/editor/ckfinder/userfiles/files/39478444627.pdf
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f277d75ec3---34345245651.pdf
    • http://www.tecnobor.com/ckfinder/userfiles/files/50086040288.pdf
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/lamodota.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/285988818cf931169376ac2c21625144/33997895335.pdf
    • http://exhibitionchannel.com/upload/58656195263.pdf
    • https://ndmoyun.com/calisma2/files/uploads/xobowefogevizulujibejema.pdf
    • https://tonerihned.cz/userfiles/file/xolunajowisepuketololose.pdf
    • http://gearcon-eng.com/file_media/file_image/file/vezixedegidedimisutunal.pdf
    • https://cosplay-expo.it/ckfinder/userfiles/files/pinokosufujowiwalamega.pdf
    • http://daiichihousing.net/uploads/news_file/98225820617.pdf
    • http://autosoftware.company/autoresponders_images/files/32599210312.pdf
    • http://preiss.at/upload_files/files/11768771430.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/2asdi25ps5e1838n97ra5h85cm/wimipuxidiforiza.pdf
    • http://metabolizmusonline.hu/images/upload/file/77468362213.pdf
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/4ftna28fe8kkt04m3asa6i7if7278fm9/tofeto.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_off0000baeb.bin
3be8b1960ac63b68687db7cb01f912baad7974719ab782c6262f513a068bff87
pdf-font-stream PDF embedded font (sfnt) at offset 0xBAEB 15168 bytes
font_01_sfnt_off0000e1b9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B9 16792 bytes
font_02_sfnt_off0000f9d0.bin
ce727106a53d6d895723ee5697c98d1172657e3aa6eef5db552095b2e724f10a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D0 10900 bytes