Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a7d69ee308c2821…

MALICIOUS

PDF

79.3 KB Created: 2021-09-12 01:45:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: dfb847a68377b3d7a25a1b125119ff8b SHA-1: 3570417d6292815deb62f39437f392e4e4f6ba98 SHA-256: 3a7d69ee308c282196f3f8c4a7e1f59f943a88a812dfb10f787c14ddeba67be9
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and embedded links, many of which point to disposable hosting and are designed to redirect users, suggesting a phishing or malware distribution scheme. The presence of 'wkhtmltopdf' in the metadata indicates it was likely generated programmatically, often a characteristic of bulk phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://irlanc.ru/uplcv?utm_term=brain+wash+game+apk+download PDF link annotation
    • http://naturalfurnish.com/userfiles/file/16589508122.pdfIn PDF document text
    • http://charmingcurls.se/upload/file/93141327917.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613996df93d67---fagima.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210909_2DD50E6DC67823D4.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/23900880635.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/29120948115.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/wosaxasumonapovojaj.pdfIn PDF document text
    • https://sambelteri.com/contents/files/71437719349.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16133063c4b39e---82160201019.pdfIn PDF document text
    • https://millersexpress.com/userfiles/file/66999551030.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/fafamoluvapejor.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/rukelavujuburunizul.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/53776780034.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210904092052.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/45093046566.pdfIn PDF document text
    • http://borneneskontor-landsforening.dk/userfiles/file/96676812591.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/785960092613b412b4951f.pdfIn PDF document text
    • https://samudra99.com/contents/files/zobudojafenovugonosilovom.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/48702391439.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/bemujobujesifivibifuwim.pdfIn PDF document text
    • https://manpowernepal.net/ckfinder/userfiles/files/37031406439.pdfIn PDF document text
    • http://tl-maskinfabrik.dk/userfiles/file/meziwudu.pdfIn PDF document text
    • http://topopentertainmeIn macro / runtime command snippet
    • 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_off0000ce2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE2B 10972 bytes
SHA-256: 668ae5eef427b1ac7480c842231007ac809697d6dbcce4848e338d5f1774ecce
font_01_sfnt_off0000e738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE738 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4A 18384 bytes
SHA-256: 6eaf207e2ba229e98906cb1d7fedd6446fc9b82e461920a8ba33ed88b5ac6791