Malicious PDF — malware analysis report

Static analysis result for SHA-256 c42ef72aa7e5f762…

MALICIOUS

PDF

75.0 KB Created: 2021-09-20 03:11:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5105927d2dc1973335e9a8ac17fcf4b4 SHA-1: c749da43ae5dfd3b5ceaf5b6043933bc669f7d40 SHA-256: c42ef72aa7e5f762c7cc6770d9d8a453e9319a02d902e41a9deeae4f4aeab740
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure strongly indicate an attempt to distribute malware or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://rtm-plus.com/ckfinder/userfiles/files/24908983750.pdf In PDF document text
    • http://bienbao.org/uploads/files/sufupiboru.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613efdd74c2b5---tujitawafixob.pdfIn PDF document text
    • http://thevalleytrader.com/files/91064596608.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e929dafdcb---33893947019.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/63150829647.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/vegofobavavobolubalonej.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109091820135558.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/40703886698.pdfIn PDF document text
    • http://csc010.com/userfiles/file/20210910130703_irgezo.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/20292761222.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210904191052.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134f9d378d3c---34759121388.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/25423679168.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/pedorubafepej.pdfIn PDF document text
    • http://kelt.pl/userfiles/file/80407412154.pdfIn PDF document text
    • http://bankerz.in/qpic/files/69216839447.pdfIn PDF document text
    • https://emartdeko.pl/galeria/file/fidobugimetutu.pdfIn PDF document text
    • http://xn--j1aii.su/userfiles/file/50363445304.pdfIn PDF document text
    • https://ikansambel.com/contents/files/lanikoxotugaxikigimusi.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e76732f18d---zafifakusetixazujajane.pdfIn PDF document text
    • http://3t-t.com/User_File/UpFile/file/20210914151758_MTQ3MjU3OTkwODI=.pdfIn PDF document text
    • http://hurtowniagrafit.pl/userfiles/file/84760130341.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=ithuba+daily+lotto+appPDF 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_off0000c28a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC28A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000daa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA1 10292 bytes
SHA-256: a45f8bb1ad193ff6de54e6b767f887aa8ba0a71599f0d2ca1718ca80bcabd7e9
font_02_sfnt_off0000f19a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19A 17344 bytes
SHA-256: cf5fa8fa6434406c25536ad08f0d80ce4acbbba794a7ce3af09b61a022216177