Malicious PDF — malware analysis report

Static analysis result for SHA-256 91aa219970da5212…

MALICIOUS

PDF

71.1 KB Created: 2021-09-25 14:14:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 86138b0b9e4aa1b9234e05e4b563aacc SHA-1: 3d4b9f2b4bb0f58a218d34df5db8552bf56da7fe SHA-256: 91aa219970da521282fffb970ed21d77e2cee4db0243be2054d5c7f042c45274
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable domains. These links likely serve to redirect users to malicious content, such as phishing pages or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=small+abc+worksheets+pdf PDF link annotation
    • http://palletgoanloi.com/img-dn/files/mekenowisis.pdfIn PDF document text
    • http://dalaichau.com/files/botizabonopij.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/dimowuziwulorokobi.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/miwituxu.pdfIn PDF document text
    • http://www.tecs4.com/intranet/ckfinder/userfiles/files/xalorukapuvodum.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1613f124a8b645---45784669266.pdfIn PDF document text
    • http://satyamtracparts.com/userfiles/file/tagesulovolezakelodonafu.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/80492628805.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/pubodivexuwojo.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/04720cb825a33363778eb9a1d023e3c6/30256619245.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/2674480147.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/73110831067.pdfIn PDF document text
    • http://luligang.com/ckfinder/userfiles/files/vemoxugurujuwodave.pdfIn PDF document text
    • http://ieltsadd.ir/cache/fck_files/file/lodubijotofeveg.pdfIn PDF document text
    • http://unsersohn.ch/images/file/19234756138.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210914091004188.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/221d30c1108c0e7781afd6eb1d0ff04e/79164358077.pdfIn PDF document text
    • http://stevis.cz/files/file/vofikadafujabevodiluma.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/64982971301.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/ad4c7d6dc21c9972136bf2ff781aaad4/23726906170.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/161321be55a5ca---61978957664.pdfIn PDF document text
    • https://www.winsum.frl/ckfinder/userfiles/files/11385844106.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_off0000b0a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A3 11080 bytes
SHA-256: 5bceed46be3267cce65a4403c87c3bb38a1e792eb2b2b61c0c688a784b6e1e3f
font_01_sfnt_off0000ca54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA54 17640 bytes
SHA-256: efdb907b0e9ad655e5f54687fa551bf912843fb1ca9a47605789ac56ae32bfb5
font_02_sfnt_off0000f755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1