Malicious PDF — malware analysis report

Static analysis result for SHA-256 b57bbcbcea10af67…

MALICIOUS

PDF

78.9 KB Created: 2021-09-15 20:24:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6d5efead5221211f67486d03cbb4e5e7 SHA-1: b631c63f63ee115db56a0c28abb959c68e65fd94 SHA-256: b57bbcbcea10af67ddf4de59fb60ee9878bb830176f020fae3ec2e9fff739ac6
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, specifically identified as a phishing trojan. Heuristics indicate it functions as a link farm, embedding numerous URLs pointing to potentially malicious content. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa9edb3967---tobenew.pdf In PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/80373597723.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/75068978288.pdfIn PDF document text
    • http://nguoigiupviec99.com/webroot/img/files/wipufitugujomovoje.pdfIn PDF document text
    • http://gaudi.tw/upload/files/7221561918.pdfIn PDF document text
    • http://tomasmrazek.cz/userfiles/file/62370661600.pdfIn PDF document text
    • http://darslaska.org/ckfinder/userfiles/files/ruwejafusal.pdfIn PDF document text
    • https://pecintajp.com/contents/files/7128577704.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/39573542932.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/1533049387.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/mubivumosagi.pdfIn PDF document text
    • https://actor-conseil.com/files/file/gotun.pdfIn PDF document text
    • https://olterus.com/contents/files/80160992703.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/xifiredozedebifisizid.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/10952992031.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/66720659260.pdfIn PDF document text
    • http://iowatriallawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/19664983629.pdfIn PDF document text
    • https://thepainter.asia/upload/files/95321832273.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/11554c8757885256890f7aff0f933726/musavuvagukekoz.pdfIn PDF document text
    • http://www.blueoak.fr/image/file/99870268232.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/56978171536.pdfIn PDF document text
    • http://nghiencuuykhoa.com/uploads/userfiles/file/98171403610.pdfIn PDF document text
    • http://newdimension.su/userfiles/file/84225069229.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/78346930727.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/kuzitiru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+create+private+photo+album+on+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_off0000d015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD015 17324 bytes
SHA-256: 92b8500a8de864afe4483c227821dfdb2779229d6c361ca6f9ce301304917ef8
font_01_sfnt_off0000fc9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114B5 10996 bytes
SHA-256: 8076dd5007edf8d21c8fa3c385792c3cbb465381a8a13bd6c6949f9615e34e0d