Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cb6b98af815c0a7…

MALICIOUS

PDF

84.0 KB Created: 2021-09-20 13:15:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 785566f946a97d532343369597fd3db9 SHA-1: c8c07956d44f65ea5452a67568106a4c7927fa63 SHA-256: 8cb6b98af815c0a7ea33489d81bd4c4a1d257fdfea6bfb5028cf23d0045b48b3
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The presence of numerous external URIs suggests an attempt to redirect users to malicious sites, likely for phishing or SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bibrka-school.org.ua/ckfinder/userfiles/files/papumovatepetowotutin.pdf
    • http://envisystem.com/upload/userfile/files/duxabovudomumevivodam.pdf
    • https://perfecthospitals.com/FCKeditor/file/29799974841.pdf
    • https://karpzbeldowa.pl/uploads/userfiles/files/80598524382.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/8284vko1ovi1n2q645j6l0mk7m/zuvinebanujanivezixi.pdf
    • http://i-akparat.kz/ckfinder/userfiles/files/xafixelibijebirol.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/nvtbnf9fusnpvig638s375a1fe/rapetal.pdf
    • https://saigonservices.vn/images/uploads/files/xegudepasijaxevog.pdf
    • https://tractorpulling-emmeloord.nl/upload/file/golebanozumavivinabuxov.pdf
    • https://a-pointpro.com/cms/ckfinder/userfiles/files/gobizivadan.pdf
    • https://clubsecurite.fr/webroot/upload/files/83992040774.pdf
    • http://montaze.org/democms/userfiles/file/24255215887.pdf
    • https://airbays.com/userfiles/file/valesejome.pdf
    • http://radio-salsa.fr/php/rs/filesupload/file/60235189880.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb1361ec42---87287306406.pdf
    • http://woodbridgeabw.com/uploads/files/19299542274.pdf
    • https://anup.bo/images/files/dusawurimowabefafuz.pdf
    • http://studiotecnicomancini.eu/userfiles/files/dipunorurobuze.pdf
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/xenosutoga.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380cf23f949---ruxifigofav.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/fl7ppd75k5rq6mjdiis477a82h/39327923650.pdf
    • https://sca-eagleegg5k.com/ckfinder/triplebuserfiles/file/fiseviza.pdf
    • https://rentcar888.com/uploads/files/202109011227306587.pdf
    • http://netisiletisim.com/guvennet/resimlerfiles/puvumebo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+get+unique+device+id+in+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e365.bin
3f16d3a2b60affe6c201ba20a7761b6a61a5acf129c17cae919012b327acf4d4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE365 17764 bytes
font_01_sfnt_off000111ae.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x111AE 16792 bytes
font_02_sfnt_off000129c5.bin
9e0c759b254e772923d5abff0a1be038b1cbfbe1e9f7f8a06a70ddb092aac4a5
pdf-font-stream PDF embedded font (sfnt) at offset 0x129C5 10720 bytes