Malicious PDF — malware analysis report

Static analysis result for SHA-256 854583709eb638f4…

MALICIOUS

PDF

72.5 KB Created: 2021-09-26 21:18:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: c35b4cf2a26758ce362cdfdf4123b325 SHA-1: e795a137522f77df278a911cdfd42ba9a16dab99 SHA-256: 854583709eb638f4108793d88199f2aa23f0b4217d7b554d3701764af38f39a4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains embedded JavaScript and a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, forming a link farm. The embedded JavaScript likely facilitates the redirection or download of malicious content, contributing to the phishing or malware distribution objective.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://nomylo.ru/uplcv?utm_term=queencee+vpn+v5+lite+apps PDF link annotation
    • http://mbjarrahi.com/UploadedFiles/New/file/bisafivir.pdfIn PDF document text
    • http://fjzy18.com/image/uload/files/36809169913.pdfIn PDF document text
    • https://minervatech.work/js/ckfinder/userfiles/files/kimoluwapumerudejudomi.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613244f0cfcb2---87072872147.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/guroleworizon.pdfIn PDF document text
    • https://planningpvedh.nl/ckfinder/userfiles/files/zetod.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/87156141279.pdfIn PDF document text
    • http://adidravidar.com/ckfinder/userfiles/files/5477800090.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/42119879274.pdfIn PDF document text
    • https://oldgradeducation.com/ckfinder/userfiles/files/10200950601.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/mugesajewur.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/82235474537.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c3c08ccba---84785170428.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/vilabivuwavebosefikoviz.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/tm83avg0ti75o18nevk6jhh8pc/nataluvibezonasa.pdfIn PDF document text
    • http://zawodydrwali.pl/app/webroot/userfiles/file/wopatilenasem.pdfIn PDF document text
    • http://jnejendomsdrift.dk/userfiles/file/rusebewileseguli.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/002255a6799ac86d78568f64b6c8471d/gutetunepofogifonofu.pdfIn PDF document text
    • http://gesundheit-im-blog.de/userfiles/file/litujexawugen.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/10604406679.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614acf748365a---zibenumirozikovo.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/062ce442933eb7656ea79af3bcb43aaa/21729687128.pdfIn PDF document text
    • http://imcborivali.org/userfiles/file/6074141586.pdfIn PDF document text
    • https://thingstodobahrain.net/ckfinder/userfiles/files/84603233545.pdfIn PDF document text
    • 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_off0000b5bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5BF 10504 bytes
SHA-256: 53f16b71a37ce40eb97df568300127570895bbff446a6bde1c2eb80c2c863da3
font_01_sfnt_off0000cdef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e601.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE601 17444 bytes
SHA-256: a8f42fd25fb3491b89e2bcbf2908f9e718aedbff73e7a3ae7002acfe2351430c