Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ec6161c594f378b…

MALICIOUS

PDF

69.4 KB Created: 2021-09-11 09:27:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7a920eea0e3f0585c65d74d668f61620 SHA-1: 8557f770fe97f745a94090e592230548cfc1520b SHA-256: 6ec6161c594f378b3547a82cc8b81202deac6fcf8fb7a10ace12b0e5f5b928ea
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDF files on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a non-clustered link farm on disposable hosting. While no scripts were explicitly extracted, the nature of the embedded URLs and the ML detection suggest it may be used for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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 http://cegled.varosom.hu/userfiles/files/rimivopo.pdf In PDF document text
    • http://haiphongcontest.com/images/files/78745664099.pdfIn PDF document text
    • https://teamcode.net/upload/files/lovax.pdfIn PDF document text
    • http://www.sauminandy.com/fckimages/file/legigiwulibinuvowuwiti.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210903210314487112.pdfIn PDF document text
    • http://leton.pl/userfiles/file/24515794614.pdfIn PDF document text
    • http://fluorescent-training.com/file/4688952284.pdfIn PDF document text
    • https://intersensor.ro/v2011/Files/fck_upload/file/newerojuxifosililabu.pdfIn PDF document text
    • https://medbioplast.com/klucharnet/images/file/76731611746.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/pixom.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/bowefivirix.pdfIn PDF document text
    • https://angem.fr/userfiles/file/98377894273.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16134dfae1e1d2---83194220822.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdb256561e---84376508578.pdfIn PDF document text
    • http://www.waetsukai.jp/system/ckfinder/userfiles/files/tikigokasadidexi.pdfIn PDF document text
    • http://195exim.com/datas/files/66399405519.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/bawoze.pdfIn PDF document text
    • http://eros-arena.name/eros/userfiles/file/zopevatoposa.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210902_205109_104.pdfIn PDF document text
    • http://jnejendomsdrift.dk/userfiles/file/71455520803.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/80156834330.pdfIn PDF document text
    • https://etravelbox.com/scgtest/team-explore/uploads/files/sivufalimegi.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/xagixatov.pdfIn PDF document text
    • https://zahidnawaz.com/UploadedImages/image/gubozan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=was+ist+ein+gerootetes+android+ger%C3%A4tPDF 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_off0000afc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFC0 15416 bytes
SHA-256: 342b33178be5f492891fe8bffa399567e7dded9a882b4d7547e25875b0e600ee
font_01_sfnt_off0000d612.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD612 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE29 10628 bytes
SHA-256: e780443163c58ed01bba764bb802c48874e622082996b57a70a555a70fb64d3d