Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c857ae51c3b576e…

MALICIOUS

PDF

79.9 KB Created: 2021-09-18 10:53:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 32355bbd38bc1806ba31129b7a38be10 SHA-1: 4d01d9f709ecb57d789aa6cb90dfa6973c375144 SHA-256: 3c857ae51c3b576e02982c70016b7896b341483b52fd3aac4b363503857e7305
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://12waktu.com/contents/files/41342362252.pdf In PDF document text
    • http://teplolux72.ru/upload/file/65590186730.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210907002808.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/5636295550.pdfIn PDF document text
    • https://vidaleve.ind.br/ckfinder/userfiles/files/43492815112.pdfIn PDF document text
    • http://gelinyuanyi.com/upload_fck/file/2021-9-8/20210908080155660053.pdfIn PDF document text
    • http://thinhhoanggia.vn/Images_upload/files/10876989799.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137fddcabe91---98883748931.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/ligugigizasogirebovaroso.pdfIn PDF document text
    • http://unixsensor.com/uploads/files/202109080501124849.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/58286141372.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/29967310792.pdfIn PDF document text
    • http://randygordonlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pikekuvuvobelomokusasafi.pdfIn PDF document text
    • https://academiapreprod.riportico.com/userfiles/files/sutonupudefe.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/8697370287.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021091105195895.pdfIn PDF document text
    • http://cloverdiamond.com/file/kiwipafarak.pdfIn PDF document text
    • http://www.salac.cz/ckfinder/userfiles/files/gimubirizumuwugavexenav.pdfIn PDF document text
    • http://0985028898.kad.tw/kads/ckfinder/userfiles/files/15503735314.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/vudowagozot.pdfIn PDF document text
    • http://sanalights.com/admin/admin/uploadfiles/file/zonofoma.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-18/20210918104451689153.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/9252353978.pdfIn PDF document text
    • http://www.extramas.com/userfiles/files/vozufobabegivefavujas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+check+original+android+phonePDF 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_off0000d5fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FD 16596 bytes
SHA-256: 32f85cd8bad04b27037c6dc1d4586ba535add837ff0c057f47061938b954b126
font_01_sfnt_off0001016b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1016B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11982 10796 bytes
SHA-256: e8b5c4516840ffc32f5467c48a8f267f92cdf423082a71cfee756f430181b8a0