Malicious PDF — malware analysis report

Static analysis result for SHA-256 87f3b33928aff986…

MALICIOUS

PDF

82.1 KB Created: 2021-09-13 14:44:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 29ea41ab8ad3c7a92a76ab3b1c1dc062 SHA-1: c6973f8de6300087eaa53608b1825821d66030a2 SHA-256: 87f3b33928aff986f5e6043b397e4830330e483b019888e9beee246f596274de
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The document's structure and URL patterns align with common tactics for distributing malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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 https://coretry.ru/uplcv?utm_term=roblox+modern+house+bloxburg PDF link annotation
    • http://pxmonastery.org/CKEdit/upload/files/82049330222.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/81694171477.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/99068049789.pdfIn PDF document text
    • http://szkolaprywatnaleszno.pl/userfiles/file/20583589533.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16138da3751c1e---vevowomotoveselojizabojom.pdfIn PDF document text
    • https://sanaspinler.net/calisma2/files/uploads/14287436160.pdfIn PDF document text
    • http://bakersfield.thepokeluau.com/uploads/files/tugarisurekivuwija.pdfIn PDF document text
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/wamakugejedaremizuduvo.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/161387499c894d---welidoson.pdfIn PDF document text
    • http://ilksolar.com/Images/Media/files/tusafumifav.pdfIn PDF document text
    • http://medwin.kr/userData/board/file/vorajevanukugazebabimo.pdfIn PDF document text
    • http://warwick-ems.org/userfiles/file/poduxujenudigipubozame.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/noxave.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210905_112644.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/29492154678.pdfIn PDF document text
    • http://wwsm-hk.com/files/file/rorovunal.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/fopasobefanopugure.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/58782051712.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/zilaxiwiriwun.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1d63b47d2---dosegevononixo.pdfIn PDF document text
    • http://kpghomerepairs.com/uploads/image/files/76591232205.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210905_BA9AE59B832A34EF.pdfIn PDF document text
    • 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_off0000dcd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD9 17672 bytes
SHA-256: de9916f5c78a419cc1525c81743c365a2715850bdfc838176159b51bbea29c03
font_01_sfnt_off00010ad0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD0 10732 bytes
SHA-256: b4d4d0d529779b122f27f8f3347295f1035dbebe6096c7c23096fed3386c4427
font_02_sfnt_off0001230f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1