Malicious PDF — malware analysis report

Static analysis result for SHA-256 c736527a4edd22bf…

MALICIOUS

PDF

89.0 KB Created: 2021-06-30 19:45:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dee6c433de3dd46ae055108af8182cb9 SHA-1: 658ead17894496ecb8b7503208eb3ba61391afe2 SHA-256: c736527a4edd22bfbb2e7aa1b954c3f4b67faf705910a51a3325294638e1d900
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm and presents a deceptive download button, luring the user to install a browser extension or update. This aligns with social engineering tactics to facilitate further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/8935ada2a1e9e330aa9cb90b255d9661/jixeka.pdf
    • https://spacio.hk/attachment/file/tegipojola.pdf
    • https://lawyerupsmart.com/tempimg/file/gebiritugevaxiwipopebedu.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160c855180a897---79155912965.pdf
    • https://tidymoney.com/ckfinder/userfiles/files/4158738296.pdf
    • https://weyergans-hcc.lv/userfiles/file/fojipe.pdf
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/322ebcae05b2ca0acfa5c2ab0e043877/33544146754.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081672d08d18---95007351733.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160a0199802a89---8118309026.pdf
    • http://scuderieverdina.it/scuderia/userfiles/file/fuwositijabewaxojemeveba.pdf
    • http://toanthinh.vn/webroot/img/files/71898389768.pdf
    • http://ctyrkolky-gamax.cz/data/dokumenty/33799189016.pdf
    • http://chixue.com/uploadfile/file/20210519175249.pdf
    • http://candientushinko.com/images/file/jediv.pdf
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/02f9c843c5848fd273f2ea5082bdf792/xidibiretuse.pdf
    • http://kulturazebrak.cz/userfiles/36810010470.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4aa036347b5cb63c1b4ca656ed4eac73/sovasadimobosenajaxar.pdf
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608631080273f---vajarifojokoxagokebevov.pdf
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/160836db49ebbb---rilofikodalexazopabij.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160705d5e33ba0---34412480314.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609faf3948378---22617946869.pdf
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8cd0740dfb---kuparusatitamamimuson.pdf
    • https://sluganarodu.org/userfiles/files/rewesovukogezej.pdf
    • http://sola-brothers.com/userfiles/file/xojofaf.pdf
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4de554f877---19383865144.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/9d7c8c354ab0898375bdf68febe981dc/museri.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bd7a373a504---gegagizaxumejofegigarugeb.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=nsca%27s+guide+to+program+design+pdf+free+download
    • 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_off0000f616.bin
a0022b708e6df537c370f70546197637945c6620de66b525c1a44b488162f842
pdf-font-stream PDF embedded font (sfnt) at offset 0xF616 17588 bytes
font_01_sfnt_off000123ec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123EC 16792 bytes
font_02_sfnt_off00013c03.bin
782951b6de24d069b10fd64f219ab9079c8a00a283e18d0c329c98410c8f423d
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C03 11160 bytes