Malicious PDF — malware analysis report

Static analysis result for SHA-256 c769393984fd6e2e…

MALICIOUS

PDF

70.0 KB Created: 2021-09-25 13:58:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d791b659f162317c9a7b1bd15c6c1a11 SHA-1: f7c79ae33cbe1616ff49016bfd47fe5a9b78a3a2 SHA-256: c769393984fd6e2eded85b7574c40f15189cfaf4dd2ed25340e8c49ed9ae6ec4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs. Several heuristics indicate that these URIs form a link farm, with some pointing to compromised CMS upload directories and disposable hosting. This suggests the document's primary purpose is to redirect users to malicious sites, likely for further payload delivery or phishing. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=if+loving+you+is+wrong+quotes
    • http://straub-online.ch/userfiles/files/badimusugogexufepi.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/wodinudodikolufazo.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613d78595c185---detemosiw.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/bl05g9lshfa5nm7e4rdlvqqcgn/94751897519.pdf
    • http://reklama-kemerovo.ru/files/files/golinifalifeforopadesez.pdf
    • http://dongamold.com/fckeditor/upload_files/file/23786668051.pdf
    • https://fivetc.vn/uploads/files/7567845284.pdf
    • http://edins.net/userData/ebizro_board/file/porunulidawomiwofaxomuwa.pdf
    • http://cuacongtudongbinhduong.com/upload/files/gewemabetorezor.pdf
    • https://bunyaminerdemir.com/resimler/files/jewogatav.pdf
    • http://onishi-kyosendo.jp/archive/16000702074.pdf
    • http://bytip.net/filespath/files/20210905004916.pdf
    • https://km2804.com/ckupload/files/31160058992.pdf
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/27002640854.pdf
    • https://washlounge.in/ckfinder/userfiles/files/xewefuzorawezozepopiduz.pdf
    • http://abc-tel.ru/data/File/vimegobulobabovijas.pdf
    • https://hygradeinsulators.com/images/uploads/file/sepawo.pdf
    • https://almondzwealth.com/administrator/imagetemp/file/96271431881.pdf
    • http://dom-2000.ru/ckfinder/userfiles/files/mafotinuz.pdf
    • http://residenzaeden-albisola.com/userfiles/files/siponenotubib.pdf
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/edpl11b4oudb8mloebnlfagrpt/zewaribonesanupol.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140ceca5da05---bipigaj.pdf
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/69579952336.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_off0000b14d.bin
21da52c37a0c2d88c40cfb70d16c6b6cf6ac83213077377c2ef2428d4072b00f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB14D 10692 bytes
font_01_sfnt_off0000c9b4.bin
e9d06eb2f1b8124f0a10243331ab2ecdd8ebfc55810ac2e58bfbadec08916793
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B4 16028 bytes
font_02_sfnt_off0000f21d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF21D 16792 bytes