Malicious PDF — malware analysis report

Static analysis result for SHA-256 538a729ebd3a6424…

MALICIOUS

PDF

93.9 KB Created: 2021-07-20 02:29:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e297bbeb87e08bdf40c1204902cd0372 SHA-1: a6312c350d00ec16959da3da255389819b8e580b SHA-256: 538a729ebd3a6424d07f82de615e3ccbf5d8b06be625b506258403e529bfcf2f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to compromised WordPress sites, identified by heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8fac31c75---kasuxabujikabirilezib.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa37af81db0---21496791057.pdf
    • http://myrbacken.se/login/ckfinder/userfiles/files/37483354581.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160704abda3cd0---vavajexa.pdf
    • http://garderoba.sk/images/_file/zezoxijaxilusemi.pdf
    • http://altiro.nl/home/tjerk/file/wunimuziv.pdf
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f18ad5bdb88---mixoxoruvuwadu.pdf
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be1be27bb95---tovizetemojib.pdf
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/d2dbfdbae002a3f150b8d0a57bb606c9/nukakizugotediwutijo.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/lgu1qb0rorr4erse6t6915kll9/wisuxubalemefatokipemobul.pdf
    • http://charugarware.com/DEVELOPMENT/charu_garware/uploaded/userfiles/file/walujowafabisedezawinore.pdf
    • https://sealordhotels.com/ckfinder/userfiles/files/57211078911.pdf
    • http://zafirkort.com/uploads/files/59031447836.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16084fc88b41e7---54452404302.pdf
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607546eb36777---67804606964.pdf
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/1459c953a3632b02a9bfc51503bc0fa8/nivafisotazi.pdf
    • http://sahamit.net/userfiles/file/9673826922.pdf
    • http://scriptonica.ru/files/files/47807116288.pdf
    • https://study4student.com/cache/fck_files/file/1561420267.pdf
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/11964ea2933855004c99db9900cbd387/pibagodaposux.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/a6938b06d03782f85b9b9b0834f98c54/resofinarodunawomoto.pdf
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/apnllemqm22h670ugdkhhkeral/tefedijez.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/a1onep33mful28snpmftdfg2t3/redenufogonitojozewowu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=fix+oversalted+food
    • 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_off00010c73.bin
33317d87b8249584cdc885816fd740aabbb5c8a8af0229c99c5738e3e79516a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C73 10388 bytes
font_01_sfnt_off00012420.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12420 16792 bytes
font_02_sfnt_off00013c32.bin
e1e2555c02db37f67ee8550e68cdee31db24513734418c734f6f957fc975e249
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C32 17860 bytes