Malicious PDF — malware analysis report

Static analysis result for SHA-256 0184da0de436b0f8…

MALICIOUS

PDF

71.6 KB Created: 2021-09-08 05:59:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6749123a48bdedb38769877f22eda991 SHA-1: a8955ca90d65189467013599c24f7193f620c15e SHA-256: 0184da0de436b0f829f44446c3820f0747077e065b769b130b5cf25a5c456026
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://pistant.ru/uplcv?utm_term=ncert+sanskrit+grammar+book+for+class+9+pdf PDF link annotation
    • http://hongdanhaudio.com/luutru/files/21344580045.pdfIn PDF document text
    • http://sun-green.de/ckfinder/userfiles/files/fagabopogimeliseru.pdfIn PDF document text
    • https://novzelandiya.ru/ckfinder/userfiles/files/69059270571.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/1019675434.pdfIn PDF document text
    • http://karinameal.ru/imgdish/files/2942560053.pdfIn PDF document text
    • http://hopkinshigh1961.com/clients/878968/File/60355482582.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c68109dcb---gaxejagoxugizadanu.pdfIn PDF document text
    • http://hanasushichoice.com/uploads/files/bizev.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce990966a20---ruzexunarusinugajikagefu.pdfIn PDF document text
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/0b2964e8ae6668029e41acbf812ab696/fulumomuralireke.pdfIn PDF document text
    • http://tv-sat.cz/userfiles/file/24093925022.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/didakise.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/4314cb35185b857cbd77af4327f18ebd/18543191503.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa50d49376---gizefewome.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161377d32e403e---51589251159.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/tudusuburexu.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16071de744e13c---89755465362.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/fexesumibikesi.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/94185261729.pdfIn PDF document text
    • https://diaspoassur.com/wp-content/plugins/super-forms/uploads/php/files/4b73f8421ca56a565a1e815b4460bbf9/nafizarebapebibofalakub.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/44216487095.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/42j4kqsbvro02djt190lm2pmn4/tujosodado.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9456f39a3e.pdfIn PDF document text
    • https://wecareu.net/ckfinder/userfiles/files/nikaferajilofibapuxowigor.pdfIn PDF document text
    • http://pro-roubenky.cz/UserFiles/File/87365673460.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/pemagozekevevonov.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/ropatas.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB71D 11340 bytes
SHA-256: 8644cb9334c613181a604741d4fa3aa1e500b633b5e35c95141688aa7fb40ad5
font_01_sfnt_off0000d16c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD16C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e97e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE97E 15176 bytes
SHA-256: 140d8d09a1075e7b16a9786c18cf9a19ab318cfd41cc248828d9d68752ae7c6d