Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9548db75a70e7f5…

MALICIOUS

PDF

157.3 KB Created: 2021-08-12 15:21:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d2dc43e84664951176a3ac35bcd5f985 SHA-1: dc0fe5dceb6d18d42f2d441740bbc9985bddb163 SHA-256: b9548db75a70e7f5dc1f6a36eb535d5a427e3921d15f6c545e1181031bd4e00d
204 Risk Score

Malware Insights

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

The sample is a PDF document that contains embedded JavaScript and numerous external links, many of which point to compromised WordPress sites hosting other PDFs. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document's content likely prompts the user to install a browser extension or update. This, combined with the ML classifier and ClamAV detection, strongly suggests a phishing or malware delivery attempt. The embedded JavaScript may be used to further obfuscate the malicious intent or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9628

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.
  • 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://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717c6ae1911---sexosegezuredef.pdf
    • http://adamlegal.com/userfiles/file/45634354208.pdf
    • http://soepcentrale-dekeyser.be/userfiles/file/45487300803.pdf
    • http://rentbucharest.net/images/userfiles/zowimugakokigarawodaven.pdf
    • http://boldino-hotel.com/ckfinder/userfiles/files/3975080853.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16073595df2dee---32120099334.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d9459df1a---vewujarebimaguxix.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/1fcb2f1dbe3a1530518ac791e352f6eb/47099725574.pdf
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/9987077809.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ff4c857be31---gavorit.pdf
    • http://altelaw.com/uploads/image/file/98437067661.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b75295dfb---5062529687.pdf
    • https://adikkedua.com/contents//files/8334178250.pdf
    • http://afgventuregroup.com/cfiles/file/nisodizodejemilojozenon.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160cbdbeb0c487---46065034231.pdf
    • https://x-software.cz/data/file/bituvub.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610393d523ac4---xabixod.pdf
    • https://penal-garazh.ru/files/fotokojikurolomowokeji.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16081dada31dab---8643663334.pdf
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/75468709288.pdf
    • http://booklandbooks.com/userfiles/file/pibasalijilo.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5s22pcd9ds4b5261lqgpkvgdv1/45732383871.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1609b76139f97c---fejupasusejobanemux.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ppsspp+best+fighting+games+list
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_009_off00024d9a.bin
51f759539ded29aada3f7f72fe377a19c1bcb521ed55937c691eb41ca2505866
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x24D9A 16852 bytes
font_00_sfnt_off0001ecc6.bin
a9c459ad7790b14fe7e9c916374dc4aa84ea2141a883161636ac51e7ba36edeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1ECC6 18544 bytes
font_01_sfnt_off00021d4b.bin
281122152296ac915129bac7266c0ce251f042997eb77719f7c28a89c16acfeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x21D4B 10728 bytes
font_02_sfnt_off00023589.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x23589 16792 bytes