Malicious PDF — malware analysis report

Static analysis result for SHA-256 557d48fbd89d2e20…

MALICIOUS

PDF

82.7 KB Created: 2021-09-12 17:22:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0aabde5f881d94a8cded068ba9e6cd34 SHA-1: 437c10525e01ff0a68313bb209eaa9e1dfebadaa SHA-256: 557d48fbd89d2e2047f9e1216e542d9f6e764e3c79cad4f32d91d0fd03ca42df
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to compromised or disposable hosting sites, potentially for downloading further payloads. The presence of external URIs and the nature of the link farm suggest an attempt to trick users into downloading unwanted files, aligning with a phishing or malware distribution tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://rjt1.org/upload/files/44097874523.pdf In PDF document text
    • http://tamtamphat.com/upload/files/89495657483.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210912211835_1352416052.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/12747173373.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/72368440113.pdfIn PDF document text
    • https://onlinendttraining.net/files/fipoxijorimezuwar.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134ae48b546b---wojagowisoropele.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd3d724d0e---65162598102.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/bemipe.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/xutamexekipupugul.pdfIn PDF document text
    • http://sunil.kr/uploadfile/fckeditor/file/4443026355.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/54957990601.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/rigozu.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff16a84aca---41939816880.pdfIn PDF document text
    • https://taxforce.nl/userfiles/files/94733636672.pdfIn PDF document text
    • http://polipadel.com/userfiles/file/fabozeduvijize.pdfIn PDF document text
    • http://igabana.com/upfolder/e/files/20210905180856.pdfIn PDF document text
    • https://abss.pt/userfiles/file/22925663875.pdfIn PDF document text
    • http://zamel2.pl/userfiles/file/dimapibif.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.info/upload/files/koriwagedikazajufekud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=download+game+sengoku+basara+4+androidPDF 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_off0000d82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD82A 20384 bytes
SHA-256: eb90bacf917cef22cec87b09530abcdcb5aa2cee2323462308ad1babe867b813
font_01_sfnt_off00010be2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE2 10988 bytes
SHA-256: 66d91f4139e682f8fe223c64270062fae34aa3048b92baa6fadba33574fb2c5c
font_02_sfnt_off0001253e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1253E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1