Malicious PDF — malware analysis report

Static analysis result for SHA-256 84d7f91820185cc5…

MALICIOUS

PDF

75.7 KB Created: 2021-09-13 13:31:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a86993a20fac0b03bba5f559e30da29e SHA-1: ebf9c8d299b1bb2c0ca8b323f02e447d80385b39 SHA-256: 84d7f91820185cc5ddfff945f980c3c15b847f0c80d397363f5c19495154ecee
164 Risk Score

Malware Insights

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

The sample contains embedded JavaScript and numerous URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious PDF files, which are designed to lure users into downloading further malicious content or providing sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/kfeqcoi0omjan7c4cfsi2s5sgq/waboli.pdf In PDF document text
    • http://fu-xin.tw/uploads/files/202109050244588586.pdfIn PDF document text
    • http://nemochem.cn/upload/files/97121825318.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/porijorapofivuv.pdfIn PDF document text
    • http://markjfox.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/folepud.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/dezixabuk.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/boneji.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/10611077940.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/butatinusipokumuto.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/38133897740.pdfIn PDF document text
    • http://zae.me/datafiles/file/raboronotupagogogovi.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/tm9tt5qnjdtulkgnhq8a59p24q/xopekawilazovitakowilom.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1631310805.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/ee8a7c6c28b8d97d6307117a3e2fe196/mufaxunirobizuvet.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/todudixixereletezowavebap.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/wulos.pdfIn PDF document text
    • https://f2h63c2.ip4secure.net/upload/files/gaduxisaju.pdfIn PDF document text
    • https://planet-pvc.com/upload/files/manop.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/23404400135.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/velokikipiwig.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/kofezusul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=the+duff+gomoviesPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B3 10420 bytes
SHA-256: 6ba883261a1145b4d2776888f1e93b8963a1a98a02f4a78bedfdec9e86e46640
font_01_sfnt_off0000dd1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1E 17292 bytes
SHA-256: b2e71b020641c66309fbc33e6f8e3ed730a836374a00cae2e294d2c94e0dc268
font_02_sfnt_off00010a3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1