Malicious PDF — malware analysis report

Static analysis result for SHA-256 82c6fbe75f7c2a3c…

MALICIOUS

PDF

87.4 KB Created: 2021-09-10 22:44:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 889253b78f3e788b70a786a7b32eb985 SHA-1: a74a771a705db3ddaebb3892d53ec70a59ce9d1f SHA-256: 82c6fbe75f7c2a3cda55255dacf5d04eccbb61b40bf51af3e88fc405ac88087f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to numerous potentially malicious or phishing sites. While no scripts were directly extracted, the nature of the link farm and the embedded URLs point towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://obkladacstvikolar.com/content/gobarebuwazokazo.pdf In PDF document text
    • http://cherryontop.pl/upload/fotki/file/bolesefokugumizefetosug.pdfIn PDF document text
    • https://esvigo.com/upload/files/kogesowenezugaxufusen.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c8fc643e4---dolijukusikuguzipe.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109040324256211.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/lijisegite.pdfIn PDF document text
    • http://werkschoenenverkoop.nl/images/docman/files/51472178924.pdfIn PDF document text
    • https://raljob.com/userfiles/file/puvitufevivoleraz.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/20667648801.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/73405883249.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613573cc002ed---bopowibeviralu.pdfIn PDF document text
    • http://huucodatlanh.com/userfiles/file/37442033813.pdfIn PDF document text
    • http://savemaxint.com/files/file/30180707730.pdfIn PDF document text
    • https://chezgregoire.fr/userfiles/wojeradabiwi.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/midepiwurig.pdfIn PDF document text
    • https://hongdung.vn/ckeditor/images/files/82315015747.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/wedifukimikofetugifiso.pdfIn PDF document text
    • http://chetaomaynganhnhua.com/uploads/files/nafinutobalamopifokenij.pdfIn PDF document text
    • http://hyunshin.net/userfiles/file/69223418180.pdfIn PDF document text
    • https://csn-alliance.com/data/files/gopikomuxajajajazixewijo.pdfIn PDF document text
    • https://colegiumaniucarei.ro/ckfinder/userfiles/files/43130259423.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/20245853742.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/dasotiraxejazaxifuzul.pdfIn PDF document text
    • http://osteriadelcampanile.com/userfiles/files/rezufazalebizudekujus.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/gixava.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=bt+cloud+app+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_off0000f34c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34C 17356 bytes
SHA-256: 847881abf56c83c0b314be47bc3b02c91219f04e964fcbb7689c7028d73937ef
font_01_sfnt_off00011fed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FED 10360 bytes
SHA-256: 5a8e2ac9d3d585c6bc78983cb7cee0e89eaa3bc5b3d6b75e6b02dab7f07c14c6
font_02_sfnt_off00013767.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13767 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1