Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e406b3df2d25412…

MALICIOUS

PDF

127.3 KB Created: 2021-09-22 14:27:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b11b7762816cbd16c29ed017ce7dfa8d SHA-1: 816ac69bfabe0106113afad27a271457cc00fbea SHA-256: 8e406b3df2d254124c1800d9aca65c0092fb9cd5a064b67fe1fe1dcf7874f2ce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm indicators reinforces the phishing and potential malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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=bsc+nursing+2nd+year+msn+book+pdf PDF link annotation
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/161480ebb10ec9---1888393725.pdfIn PDF document text
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/79731233025.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/regijulupapazuvulinejigiv.pdfIn PDF document text
    • https://dukra.sk/editor_uploads/files/93148462300.pdfIn PDF document text
    • http://sitarofindiamd.com/userfiles/file/vevakapisijabale.pdfIn PDF document text
    • https://hinaweb.com/upload/file/kifatajuvudirule.pdfIn PDF document text
    • https://biodez.lt/i/File/43172304619.pdfIn PDF document text
    • https://kristinanamaste.eu/files/79290945260.pdfIn PDF document text
    • http://sibmaxi.ru/userfiles/file/28489871378.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/7684133698.pdfIn PDF document text
    • http://balbu.hu/uploads/news/file/50596156307.pdfIn PDF document text
    • https://namhunglogistic.vn/site/files/12529078967.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/71116033138.pdfIn PDF document text
    • http://fskyok.com/uploadfile/files/bibivagusumixotobixes.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130882d1ac21---wunagizakuk.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/26912788568.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210902050343.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/levajitop.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/fojebisamazumometil.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/kovonukolowiguwowotig.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/hqa25r7t6dgku32i0p19fe829g/39615632907.pdfIn PDF document text
    • https://kar360.com/resimler/files/malavukunisi.pdfIn PDF document text
    • https://wsbtitan.com/images/file/fujaletulifomejodanale.pdfIn PDF document text
    • http://maxbrio.kr/files/files/nolonoma.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_off00018856.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18856 19952 bytes
SHA-256: 7a9e03ef1224d664d7bac6c4b95649e096c32ee4ff05fc01ae2160e1149bd306
font_01_sfnt_off0001bc51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BC51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001d468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D468 11436 bytes
SHA-256: c865efc93f78a775eafcaf029e59dd94d052f4ab8bf53afc114b6310fc5c8883