Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab50951361772b28…

MALICIOUS

PDF

86.0 KB Created: 2021-09-07 06:11:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fee7c79a23bab32b25aecb17257568c0 SHA-1: 25a0a0d03b0fe862e0317024f723cd3b85b6752d SHA-256: ab50951361772b28d057e04727679f1df4e0a879c83892931082e0a69b4adfac
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to compromised websites, likely to lure users into downloading further malicious content disguised as software updates or legitimate files. The presence of multiple PDF links on compromised CMS uploads and disposable hosting reinforces the phishing and distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://poltinka.ru/userfiles/file/nifazufawivenizake.pdf In PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/7030409081.pdfIn PDF document text
    • http://kangs78.com/clients/66216/File/bafes.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/16098d9e03a152---fupoloseguw.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/xupulora.pdfIn PDF document text
    • http://parquessolaresdenavarra.com/userfiles/files/pubemuzi.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/vpgttv75shr8q0tkqqeqcr8c54/wijusafeminojuxopewat.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/22925288491.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/36102043084.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/810c3977a97d357b4ed3c1a5fca6bdad/rikugupezazuvemodepi.pdfIn PDF document text
    • http://billsky.ee/files/file/ronamemigilonu.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/ratofu.pdfIn PDF document text
    • https://cevhertemizlik.com/userfiles/files/40971910440.pdfIn PDF document text
    • http://conroeclassof72.com/clients/d/de/de0acc14889d5d69ce6a2e221f3e79cd/File/kogiwemopigalomevup.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609645bcdf6fc---jajogex.pdfIn PDF document text
    • http://thesetnews.com/images/fckeditor/file/80768442506.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/fumesusuzojopebida.pdfIn PDF document text
    • https://viettrungson.com/media//Files/sopaga.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/13876413039.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/38139074217.pdfIn PDF document text
    • http://cuacuonductudong.com/upload/files/40085987677.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/f9e377f3a4095edf077a5202f35f8c53/88712960534.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/kofiwuladibaxeluz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=pdf+reader+editor+free+downloadPDF 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_off0000eab0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAB0 10268 bytes
SHA-256: cb4953e2ef26e1b4ce1c0d0f80ace4b199537e5eac74fdae3a200e845b03bb48
font_01_sfnt_off000101e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E9 18612 bytes
SHA-256: a5af60a3978b00b56c8372f1f2732477fd0c41c9bd17e53b796c7940a8a715d5
font_02_sfnt_off0001321c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1321C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1