Malicious PDF — malware analysis report

Static analysis result for SHA-256 539f6c7112c5b16b…

MALICIOUS

PDF

70.9 KB Created: 2021-09-28 03:53:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4963db3dc73b31720bac739af193e7f8 SHA-1: c864f3490b65d53b8082be6fabd1bb5ebfa42f0b SHA-256: 539f6c7112c5b16b0dcec08a1de66dbf07b08f06da0e73e8b15da22f683ae294
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs, many of which are part of link farms hosted on compromised CMS uploads or disposable domains, suggesting an attempt to obscure the final destination. The presence of these link farms and the overall structure indicate a phishing or malware distribution campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://pistant.ru/uplcv?utm_term=how+to+send+files+via+bluetooth+iphone PDF link annotation
    • https://villanakarin.com/userfiles/files/59374041672.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.org/upload/files/lutodaj.pdfIn PDF document text
    • https://mehreganimaging.ir/images/upload/files/71037707930.pdfIn PDF document text
    • http://vzwsportenmuziek.com/content_docs/bepegufazotowovipat.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/61487898950.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/37825670081.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/54493714611.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16130cc52a03b1---wevenijipidevovojopisibe.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/jodaxuruxivagewuw.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/b4f4rpc09bmfl3kc3mmep31ddb/61496567989.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/nodojirinet.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/59566726386.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/2021921651360415.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132e2d507e0e---23100484263.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210917155022124.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/kekate.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/72908910824.pdfIn PDF document text
    • http://image.dlib.vn/libedu/news/bvu/20210917/file/gijaxagogosugakugub.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/vijixaterugemozimifavo.pdfIn PDF document text
    • http://hoinhikhoavn.com/img/files/zugemepuxivinosaz.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/pojopamafopikol.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fafdcab684---98391758117.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_off0000b2b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B7 10876 bytes
SHA-256: e93b8e2b0820e8e1eff9636d3094ba1ca104796c4fb115e44a2fdcdc0887e4c4
font_01_sfnt_off0000cb92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB92 16704 bytes
SHA-256: ced8f9e1af194b91d1db9dce80c2c7f5e86e90e2783d22966ff2d19ceec431fd
font_02_sfnt_off0000f5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1