Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c491971cad89aa9…

MALICIOUS

PDF

71.4 KB Created: 2021-09-29 01:20:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f3d8538f360e7221823019511eebd141 SHA-1: 6f7ff1f93ce4a636fb692b8234578624822dd988 SHA-256: 4c491971cad89aa959629ceee535dbbd3ff33294778ab358edbb3c549629a227
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://smidgel.ru/uplcv?utm_term=alexa+app+for+computer
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/8a9ff29e59a733b935c1d9f6f9794c6f/43258353989.pdf
    • http://firesecurity.sk/userfiles/file/vogegizisusidokakuruvaf.pdf
    • http://aliguoriarchitetto.eu/userfiles/files/74322601113.pdf
    • http://palakkadtourism.in/ckfinder/userfiles/files/77114360068.pdf
    • http://tks-forever.com/upload/2021/09/06/file/5075090863.pdf
    • https://vgi-vn.vn/app/webroot/img/files/kimofe.pdf
    • http://royal-pizza.eu/files/file/dorigutijafonexulefuk.pdf
    • http://conganbacgiang.vn/app/webroot/uploads/files/gawijuzixakigo.pdf
    • https://thehealerspoint.in/admin/userfiles/file/86960806099.pdf
    • http://becucci.it/userfiles/files/vusotulovivekewevud.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137759979992---72450978661.pdf
    • http://eastcity.hu/ufiles/file/25532509260.pdf
    • https://zakarpattya-tour.com/upload/9015547588.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/1d018e22e7148babcc35dd5a2addca26/60499689598.pdf
    • http://www.hro.ait.ac.th/js/ckfinder/userfiles/files/fageze.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/0197ae49960980080bb0584f7558f0a4/kixusubosetina.pdf
    • http://herborgthailand.com/file_media/file_image/file/9433648762.pdf
    • https://lyna-garage.com/htdocs/cljr/data/files/wixafubipuwu.pdf
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16151fd769ae39---janupadorakeruro.pdf
    • http://posicert.com/upload_fck/file/2021-9-26/20210926070408188507.pdf
    • http://evaemlak.com/userfiles/file///gekuwibakivovobolexoxezi.pdf
    • http://theemasternetworker.com/ckfinder/userfiles/files/64973461025.pdf
    • http://bajajsports.com/userfiles/file/zexarigudunapamusi.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/b7b88ffeacd49f2ee0857089487a7011/wadisabikijamafu.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_off0000b24a.bin
890b92ab069244147ad93b1892722aad612fb816303f9068d1d9abd05066965b
pdf-font-stream PDF embedded font (sfnt) at offset 0xB24A 17892 bytes
font_01_sfnt_off0000e08d.bin
8c3cba5f8ed53c901f531bb330a737a13b4487a61b47c781a7cc9978ce01fb17
pdf-font-stream PDF embedded font (sfnt) at offset 0xE08D 10460 bytes
font_02_sfnt_off0000f868.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF868 16792 bytes