Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbf3b39132d0ba1a…

MALICIOUS

PDF

86.9 KB Created: 2021-06-26 06:48:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 186a47aef167220591427195fde75aa3 SHA-1: ea170eb1f5e5b642354d0f2688ead41d416baea3 SHA-256: dbf3b39132d0ba1ab0ea855bd1434471f1107ca76506fce27abec82c3130f594
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://yorktownhs1987.com/clients/57482/File/juzepidumepopugem.pdf
    • http://etcad.net/np/upfile/file/masiw.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5882e8515---78114889825.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607469174ffef---mevadekadidawizo.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/kep8a9r4hpgu7sgastp7sdi962/85692454954.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fdb6bc4cf7---voturajosuketoj.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a46a01f14f5---jowiminidizuxatixabesoma.pdf
    • http://krevue.cz/UserFiles/File/jesejupuxagetod.pdf
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/4103ke7jlho7skst0t4sgaeep2/82045243438.pdf
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/2k7bj4fbea48hr1uvqnjik2rvr/fodof.pdf
    • https://tourpon.kr/FileData/ckfinder/files/20210616_21C053EBD546622E.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/qslr7vo8n0l5jurcimhrgmrqo2/33532881792.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a813edd90c9---23244661224.pdf
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/71hbt9iu4q6effc351jnkno3n3/58159160640.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/p2cji2mv4uk8sb4fjctofl69k8/bulugogagawajerogifezugo.pdf
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/mumomixisododud.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/2bffe839c8621a41c53bc7d0e153e2c2/30303115767.pdf
    • https://abugfreemind.com/userfiles/file/72611917316.pdf
    • http://xetaihyundai.net/upload/files/siwexadotopujumel.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160833e1f2cf8a---megunug.pdf
    • http://shethof.ch/cgi-bin/dynamisch/file/71561284649.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/oev7l5ktrrj1smu7p7lds4eiig/mivalimamomuvodoxib.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a96b44cc6c5---26325017609.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab3cdc011e---26283644976.pdf
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d95c45636---17973281593.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=the+meaning+of+inferring
    • 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_off0000f0e8.bin
738432512d12f03aef6ed9683f149bdba797469e60d2131277fdc32636454a80
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E8 17628 bytes
font_01_sfnt_off00011f31.bin
bc04f1ee0bd397e7db8b152a4566cc86e882d825438b2da908b7e7d504e7acb1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F31 10312 bytes
font_02_sfnt_off0001362d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1362D 16792 bytes