Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3913843f4d50e20…

MALICIOUS

PDF

78.6 KB Created: 2021-09-20 10:08:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d32b073c9dd3a7e17e565c04a69c4e0f SHA-1: ce548951013d03cdea92eb722ad2de875ccac0ee SHA-256: a3913843f4d50e20bf46882bd67c013a703ecbf5367f7ce2017957d4dcf1cb8f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs that point to external resources, including compromised WordPress upload directories. The presence of these links suggests an attempt to lure users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://nomylo.ru/uplcv?utm_term=ygopro+percy+android
    • https://groupburuemas1.com/contents/files/folok.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fcc32b8db4---90367208511.pdf
    • http://caopump.com/admin/userfiles/file/memare.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614822a847789---jinexipajukopetilikusa.pdf
    • http://langyupharm.com/upload/files/jeposolotuvixup.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9b40036bf---wususesabisujiziz.pdf
    • https://dnm.tw/uploads/files/202109062147529391.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c819a3c84---xukolapiwuwuti.pdf
    • http://gokea.org/upload/editor/files/84081522343.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16147adb28612c---33829959092.pdf
    • http://romovi.net/sgi_userfiles/userfiles/files/wajovabonasefif.pdf
    • http://happinessgown.com/upload/users/files/84866690817.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133953c1cedf---pomogefa.pdf
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143ad5262f7a---xoparorimape.pdf
    • https://adamant54.ru/userfiles/files/90515462344.pdf
    • https://habibitours.com/ckfinder/userfiles/files/godusodamuwanavel.pdf
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/52006714054.pdf
    • http://gotoippc.com/ckfinder/userfiles/files/solujezuwonivukadafuweli.pdf
    • https://altaitur.com/ckfinder/userfiles/files/95200631962.pdf
    • https://royal-art.pl/uploads/userfiles/files/1728549974.pdf
    • https://okinawa4d.com/contents/files/negoxalimuz.pdf
    • https://mobilpetrol.olajpark.hu/files/files/19248844489.pdf
    • http://fishtech.org/uploads/userfiles/file/file/motobob.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf29.bin
bffc211d150f2829b93f839397333aa5173b740b882cd6cf08e115426fbf30b2
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF29 17708 bytes
font_01_sfnt_off0000fd06.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD06 16792 bytes
font_02_sfnt_off0001151d.bin
c911c88d4032e10418252b514e897233191842d2937f9bceaa92a80ad2330808
pdf-font-stream PDF embedded font (sfnt) at offset 0x1151D 10476 bytes