Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd12818e1d27c05d…

MALICIOUS

PDF

82.2 KB Created: 2021-09-10 14:56:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 10dab9a1082b5fb1fd9cc0f68d27f1e0 SHA-1: 5d31b55e99bbd754d369f08dfa28deb58d943ff9 SHA-256: cd12818e1d27c05d5748762a19ac9487f768e585a13e6fa84b3112a8ff379824
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the document functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting. These links likely serve to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/cf645b0d60a9952e37b2a723b86240ec/tagal.pdf In PDF document text
    • http://guowangcable.com/d/files/82267325094.pdfIn PDF document text
    • http://storemisr.com/uploads/files/fivibujekimoso.pdfIn PDF document text
    • http://longarmquiltingacadamy.com/fckeditor/userfiles/file/62395448663.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210908_67A59D29D0EC0D39.pdfIn PDF document text
    • http://adhunikjewellers.com/ckfinder/userfiles/files/4326690058.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/79733537954.pdfIn PDF document text
    • https://zmiz.hr/userfiles/file/jadamepi.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/15186332458.pdfIn PDF document text
    • http://ibb-online.ru/f/file/52899565508.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/tear13dvmnvgtqcs2urvt2iod5/kigijalerafeg.pdfIn PDF document text
    • http://ryanoomen.nl/uploadimages/files/sevamazebugofexunufe.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/3f500648023b961be7ea8d88f84c98af/18588829662.pdfIn PDF document text
    • http://wanyuantemple.tw/userfiles/file/85682593943.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/30414244512.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/fopugip.pdfIn PDF document text
    • http://phongthuyphatloc.com/luutru/files/jepanedodemexowup.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/kifefemawifavove.pdfIn PDF document text
    • http://ipoz.pl/userfiles/file/vitovuzinokase.pdfIn PDF document text
    • http://odumakus.com/uploads/files/42240654800.pdfIn PDF document text
    • http://gesundezellen.com/neu/userfiles/file/jopepivekunepeloruxez.pdfIn PDF document text
    • http://stark-tools.ru/images/uploaded/34493869311.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210909200017.pdfIn PDF document text
    • http://nhakhoasaigonkimcuong.com/uploads/images/files/15368841406.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=barbie+magical+fashion+apkPDF 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_off0000d93a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93A 18548 bytes
SHA-256: ad05d60531d8fd82dcad5646e0c696f53e1adf882087af51225d48fb4710583c
font_01_sfnt_off00010986.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10986 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001219d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1219D 11112 bytes
SHA-256: 7469130dc995eb412425bf9fd62a17ddbe15df982a7e5dd0567355982580279c