Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d3d94b5b930f9d…

MALICIOUS

PDF

74.8 KB Created: 2021-09-18 02:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 063ece6bfe45c1de0d389cbfff3c1246 SHA-1: 70296ff4b9d7f042c7c40b8a0ce237583a86bb10 SHA-256: 21d3d94b5b930f9d1a94d577df359b4f6276f3d036f35bbf2017742b6e95f7e5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 7

  • 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.
  • 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 http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144a6998854d---80316394951.pdf
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/dutozumun.pdf
    • https://onecre.com/images/content/files/vifovesifusosos.pdf
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/83540635009.pdf
    • http://everbeenmagnet.com/js/upfiles/files/gabikudosojixizovaz.pdf
    • http://mtsp.by/userfiles/files/mevamuzifapiminug.pdf
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/lewagabekivigilof.pdf
    • http://scuolascifondocortinadolomiti.it/userfiles/files/41529763645.pdf
    • http://kcde.kr/userfiles/file/vifedezokam.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/499583f084a031600d739f22371d2d2b/74110079458.pdf
    • http://hainfelderteich.at/kusilok.pdf
    • http://chengzechem.com/upload/files/butaniroke.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141638427c9c---gafupume.pdf
    • https://dynasty888.com/image/files/20210912_092927.pdf
    • http://kiavysocina.cz/UserFiles/File/53664127827.pdf
    • https://fotoprint.lv/downloads/file/64198041920.pdf
    • http://heatexchangersolution.com/upload_fck/file/2021-9-18/20210918061441245808.pdf
    • http://fvv-hohenfelde.de/sites/default/files/files/kuvilevur.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/b7b67b0a797ed1472075c198b8ae60e2/mazotifuwusikixofen.pdf
    • http://jumpstart.mobi/ckfinder/userfiles/files/xumumexebiwo.pdf
    • http://texinpack.com/uploadfile/file///2021090516233219.pdf
    • http://soncongnghiepjotun.com/media/ftp/file/mizugazanezetok.pdf
    • http://underbutter.cz/download/foto/zijogilimiw.pdf
    • http://kag.fr/userfiles/file/xekosodimararegulofamava.pdf
    • http://daithanhnam.com/upload/files/53611219777.pdf
    • http://mudrberanova.cz/userfiles/file/87778824897.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=mod+hill+climb+2
    • 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_off0000c34e.bin
c5734ff3ca8884bfc9282cb516b708bfcb4b17da8a7f4afbbd2dac3a39f8b249
pdf-font-stream PDF embedded font (sfnt) at offset 0xC34E 10124 bytes
font_01_sfnt_off0000d9cd.bin
cb3881085ee01a9c3346ddc14fcb83ee83f4190b6e31f345d75ac8aa0661e838
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CD 17120 bytes
font_02_sfnt_off00010542.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10542 16792 bytes