Malicious PDF — malware analysis report

Static analysis result for SHA-256 cac1fb64d90a990f…

MALICIOUS

PDF

74.9 KB Created: 2021-09-21 10:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bbb94ae0dc70e49cef0a7f4c040eccbb SHA-1: e059b5097b3349f7da2009d5f1e6ff8f3621fb34 SHA-256: cac1fb64d90a990fad9b3ff41926f669f9a07c5dab8ae4ce2c46cd909e9de468
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating it is likely a phishing or trojan delivery mechanism. It contains numerous external URLs, suggesting it is designed to redirect users to potentially harmful websites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the idea that this PDF is part of a link farm, likely for distributing malware or conducting phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crewmak.ru/uplcv?utm_term=pr%C3%A9position+de+lieu+exercices+pdf PDF link annotation
    • http://modero.vn/upload/files/2021666196.pdfIn PDF document text
    • http://acrclubinversores.com/files/galeria/files/lititepodubakexuserugam.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/22592349815.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/tegowo.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318486ec0cc---vufaxuxivanuwugazupapi.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.com/userfiles/file/5998164783.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/1777814465.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/13964384975.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/zibulinivupatizagesoxap.pdfIn PDF document text
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/84532144273.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/29333616979.pdfIn PDF document text
    • http://gurmanosypsnys.lt/userfiles/file/75635518207.pdfIn PDF document text
    • http://0048.pl/48files/file/sowesegofinu.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/mupesolonofowiximab.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348b7a8a9d4---jabib.pdfIn PDF document text
    • http://radio6deenero.com/uploaded/files/33241758761.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/74663355700.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/75878282907.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/sumeruwaxajatefenevoj.pdfIn PDF document text
    • http://3t-t.com/User_File/UpFile/file/20210918125954_NzgyNTM5MDMwNzM=.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/57633990268.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_off0000b99b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB99B 19816 bytes
SHA-256: de8b8ef8323715cb262a610fe655123637ec889c92b329a335475b14853dc963
font_01_sfnt_off0000eb5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10375 10808 bytes
SHA-256: 3a9366ea6c77e73f42afd3e43eaea0c4c89ccb0f2fa0e6a0b3ff090c6a90354d