Malicious PDF — malware analysis report

Static analysis result for SHA-256 931f2ee21cfae7c9…

MALICIOUS

PDF

82.8 KB Created: 2021-07-24 19:06:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 68a197b09faffd2028a3c15d84680719 SHA-1: 316becd43210ce9941e6a9364f4a3cfa9af91ad4 SHA-256: 931f2ee21cfae7c9478c07cc3f6b9df519ae53451aa48b809fc86f9a8fa7ce0d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to disposable hosting or compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via a link farm. The embedded JavaScript may be used to further obfuscate the malicious redirection or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://omonetach.pl/foto/ilustracje/file/kidatobebulanovedo.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/6tshah5bs8s6s5ditb14o4g67p/murib.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/d66aaaf34910e3e90d21f1935c807976/54238182084.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/16097725d89043---bogaziruru.pdf
    • https://saatyapi.com/upload/ckfinder/files/jotaripolugavonixapiwado.pdf
    • http://aedelsur.com/contenido/files/mevolosorigiparupoga.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/6a28e0fe3eb57af6fbafd04ecb4c227a/wopunujepozefa.pdf
    • http://mcenterdk.ru/fck_editor_files/files/30819989552.pdf
    • http://a9188.com/upload_files/art_files/files/20210704_080609.pdf
    • https://kingyao.com/uploadfiles/files/20210721_043514_5461.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160984d0829181---nijevaw.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd63f6de6f---lolixererevenosadinajame.pdf
    • http://thebankcardservices.com/uploads/files/revilewebib.pdf
    • http://studioboscono.it/userfiles/files/bezotukadosa.pdf
    • http://due.pt/js/ckfinder/userfiles/files/8784658209.pdf
    • https://tjpapigroup3.com/contents//files/94432068503.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/969106b083fb9fb56865f998c814e821/romojefigedimoniji.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/e807fb1ab2559042425c6ec0fa2940e6/mevebovijudurawomilaxiw.pdf
    • http://saxonsaxtonfamilyreunion.com/clients/f/f6/f6d0431f970e0833b0867c311dafb132/File/jasutaruzudomebumum.pdf
    • http://fandimnarodaku.cz/upload/file/96649366438.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/2281b2b3c8fe05dc82d4f8bfd889de9e/82964526106.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/af047ad5d381c4988552d2c75dbba328/suvazurasop.pdf
    • http://stananddiane.com/clients/6/67/672a2699e369d648dd23e03de9deda78/File/zapili.pdf
    • http://qzgj.cn/upload/file/vuxemugonila.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=lagrange+error+bound+example
    • 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_off0000de94.bin
a8026bd3b38a8bed04e0b896f6a0422857b925371379307744ec39dc800517dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE94 17500 bytes
font_01_sfnt_off00010d22.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D22 16792 bytes
font_02_sfnt_off00012539.bin
c785216bbb78e4c7ab63f9430f5be7800f158136156841e0f8573b6c1be976eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x12539 10676 bytes