Malicious PDF — malware analysis report

Static analysis result for SHA-256 55e3f235d7bcf577…

MALICIOUS

PDF

81.3 KB Created: 2021-09-13 18:06:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 0bae3f5ce91b96e5187a3c4d59da4bc6 SHA-1: 2615c165ad86e7e48feef6c9b7d272af31a5bb9d SHA-256: 55e3f235d7bcf577b4b10d30c9a1772bd0c53d117a722ea605d169dca450f85b
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable hosting domains, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely involving exploitation or redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://mbbs.hr/files/kusugatipudadopukifapax.pdf In PDF document text
    • https://debcopharma.com/userfiles/file/soratojefumema.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/28742480131.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/juvujusixonogumod.pdfIn PDF document text
    • https://magiccat.pro/ckfinder/userfiles/files/53011323889.pdfIn PDF document text
    • https://mbamantra.com/ci/userfiles/files/27756472970.pdfIn PDF document text
    • http://erfaspot.com/resimler/files/42826606907.pdfIn PDF document text
    • http://195exim.com/datas/files/dugixobeti.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/23494272209.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/1402ee4db07bc2825f03f488d554e698/98620032538.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/bujazuxulag.pdfIn PDF document text
    • https://dawnraytech.985.tw/data/file/userfiles/files/38441804254.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/xusofejapafebezefa.pdfIn PDF document text
    • http://abcbyspu.net/ckfinder/images_store/files/romevoroketubabogix.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210912012719.pdfIn PDF document text
    • http://adgroup.co/userfiles/file/6265978673.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/7pgrsrikopenphjudssl4665ag/57184377955.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210905054326.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136d58901b6e---69411842816.pdfIn PDF document text
    • http://xn--h1agcmh.com/ckfinder/userfiles/files/65225539862.pdfIn PDF document text
    • http://grabnerestriche.at/35935247377.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/jinimusaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=std+10+social+science+book+pdf+english+medium+gsebPDF 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_off0000d56c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD56C 18192 bytes
SHA-256: 7be6d4b0694289c77a8c04cf8a3f63054f9d8b5e47feb37cd88a6c5067d4d754
font_01_sfnt_off0001045d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C74 11548 bytes
SHA-256: 31e4d5231ff17345f8b98e4b61ec759b0bc933850e0c4650af720c0a2603f854