Malicious PDF — malware analysis report

Static analysis result for SHA-256 636657760cc2d5f0…

MALICIOUS

PDF

85.4 KB Created: 2021-09-01 03:06:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 43a204e23f0e55a4bf75ff9c67f27877 SHA-1: 83c278a76a764b0c36c88a05eeebddd55fc23fcc SHA-256: 636657760cc2d5f0a79c9522bc8bd3303977b6576081ee1c0f4ac32d7be6e0c9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple compromised CMS upload links further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://kozelsk-adm.ru/files/uploads/files/viwiwabumoro.pdf In PDF document text
    • http://bwlpsalisbury.com/uploads/files/pofan.pdfIn PDF document text
    • http://miele-service-center.ru/uploads/files/dobigipamelejopupero.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/16250788911374809278.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874385ce838---rudujimulib.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/n6vfrvoe3ov6gjqd8cf0btq049/lusitawelababorudufa.pdfIn PDF document text
    • https://lwim-ouargla.dz/ar/files/85639629670.pdfIn PDF document text
    • https://bocion.com/ckfinder/userfiles/files/59393048528.pdfIn PDF document text
    • http://novussiteyonetimi.com/uploads/file/kutidefijitezize.pdfIn PDF document text
    • https://www.campacinter.com/image/upload/File/luxakezawamepur.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/cb8e1bc2a4600845be0c24f022bafd1a/vituzore.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/a7ca1af29143bead53b9d9b2e63b8751/judakatogoxulisatukipamek.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/h9dl1ldfvjj2nlt8fjoh4l31vo/94903128378.pdfIn PDF document text
    • http://cybernet-ap.com/UserFiles/File/98083287815.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160adb6d70059d---14957731476.pdfIn PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/36041793994.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/07/24/file/timeduje.pdfIn PDF document text
    • https://badrivishal.com/media/14151665255.pdfIn PDF document text
    • http://samilove-payitforward.com/clients/f/f9/f9b0b202ed5d2cb263a89f8a9bd08a94/File/62406202926.pdfIn PDF document text
    • http://cka-shiba.com/ckfinder/userfiles/files/46545505555.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/nexozefodosas.pdfIn PDF document text
    • https://delta-relay.be/userfiles/file/sorademakis.pdfIn PDF document text
    • http://travelshops.pl/userfiles/file/risuxusevobafifinujume.pdfIn PDF document text
    • http://careerdynamic.com/clients/3/3d/3d9dba0a3645e5854abf1db7654b9c86/File/rujawatutipeb.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/fumeka.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/32228611752.pdfIn PDF document text
    • http://dekogard.net/deko/veri/_files/potujilamanovo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=tiny+bees+in+groundPDF 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_off0000eb44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB44 10436 bytes
SHA-256: 1431f4cebc7bed60a76605486c28bb0edff72230df04c22feab83afd1bc5ebb1
font_01_sfnt_off000102d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D6 17324 bytes
SHA-256: 8876a55358735a0b649eff2c4c7a5991b3b068e3a315b47faece11226b1f5373
font_02_sfnt_off00012f8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1