Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b27d51b94b3350…

MALICIOUS

PDF

68.6 KB Created: 2021-09-29 03:47:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a4a00976a9010e43542ef49dc77787a2 SHA-1: 988eb33185eeba0d8d1149c5be8c83474aed7dfe SHA-256: f4b27d51b94b3350e1cb7f361db089f76329b09b02fdc18ef7af3c1dfff236ba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URI heuristics further supports this attack pattern. No scripts were extracted, but the overall structure and URL distribution indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://crewmak.ru/uplcv?utm_term=cooking+express+2+mod+apk PDF link annotation
    • http://solarexperten.ch/fckeditor/editor/images/file/pukenevamemiwozutewewalox.pdfIn PDF document text
    • http://sanarina-coaching.de/ckfinder/userfiles/files/pokuzigivikibunazaguk.pdfIn PDF document text
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/27141201196.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/56225682188.pdfIn PDF document text
    • http://yksskj.com/ckfinder/userfiles/files/76097423632.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/26981839528.pdfIn PDF document text
    • http://myshiou.com/uploads/files/202109261808158203.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/xejoxiwepog.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/kigenixorunivolap.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/basetemutetamaka.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/1c5cfc54b4c3761112455d0fca4cd184/vuwikeran.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/77420860874.pdfIn PDF document text
    • http://xn--b1agaa2anfqdp.xn--p1ai/ckfinder/userfiles/files/jelodotojejubumetagaza.pdfIn PDF document text
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/vopabobapojerolena.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133414d40b4e---29743046545.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/zizidotuzepadorimapabiz.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393d90d2ad8---63057223937.pdfIn PDF document text
    • https://cebubigsellers.com/userfiles/file/362559083.pdfIn PDF document text
    • http://zehanbiopharma.com/upload/files/vonusizutatafiwumozo.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/fivasusedixa.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/razovukamekugo.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/befajogapojexenagiresije.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/86155715048.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/wuselim.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/vubivenis.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_off0000b00b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00B 14268 bytes
SHA-256: 5364b31c7c42e05e7d2cbecdfb6e132b2ff7a8fa76255178f57bba4df66fe8fc
font_01_sfnt_off0000d3be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ebd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD5 10936 bytes
SHA-256: 270409bd759df6169a4f052e93a9294fb4232e56667b573a3c07cc4cf3b4bbf8