Malicious PDF — malware analysis report

Static analysis result for SHA-256 2ef72c51eea54543…

MALICIOUS

PDF

72.1 KB Created: 2021-09-12 03:15:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 935d616a75ce6c74f2828ef1d12d1a0a SHA-1: fb87c4fc4fc17ec4fd041adb0f54ab71fecfbc07 SHA-256: 2ef72c51eea545436beb668f20ba79464bc37d6ee88c0260bdc0d298896f4ee8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, with several heuristics indicating a link farm on compromised or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or directing users to further malicious content. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://odesignlab.ru/admin/ckfinder/userfiles/files/judosajarixemabubisenoj.pdf
    • https://iieng.org/editor/ckfinder/userfiles/files/27362968668.pdf
    • http://zoltysnieg.pl/pliki_wyswig/files/tonimunaluv.pdf
    • https://bawaniint.com/ckfinder/userfiles/files/tegoguvipenowefobuz.pdf
    • http://2446665a.ru/ckfinder/userfiles/files/31274475739.pdf
    • http://sbsedupatti.com/sbsedupatti/userfiles/file/nanideli.pdf
    • http://mnarch.it/userfiles/files/sapaviwarikudok.pdf
    • https://phukienbep.net/media/files/tawapolaxa.pdf
    • http://riph.pl/userfiles/file/nofuzemanedobaziroso.pdf
    • http://mousike.it/img_ins/files/71225393712.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a0d0c52de---towajodadonetolir.pdf
    • http://thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/16785981892.pdf
    • http://www.rajpuc.pl/pics/file/59619455321.pdf
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/39283658789.pdf
    • http://ondrejkocar.cz/img/file/nijutabatakawikizedipu.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139a3ecad5a3---kakosiwumisopelap.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b404187f0---23831486235.pdf
    • http://anindecor.pl/files/file/94750735917.pdf
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/22757676518.pdf
    • http://le-bouquet.be/userfiles/files/93791949129.pdf
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/keluvexikuro.pdf
    • http://lagrupacio.cat/file/4017855782.pdf
    • http://pitin-akutsu.com/js/upload/files/7340214277.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=gun+strike+shoot+killer
    • 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_off0000b477.bin
48aff4c60deb3fd091c5676c79a35b0ee2da1d9fe215a14635e94c862c77b2f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xB477 10276 bytes
font_01_sfnt_off0000cb8c.bin
f062206994148d67fd3c24c44ce9a34aa8d14bc42213ab303b49ee459ddf6257
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB8C 18488 bytes
font_02_sfnt_off0000fb54.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB54 16792 bytes