Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31bc592d3df6b31…

MALICIOUS

PDF

83.1 KB Created: 2021-07-06 16:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7846f7cb8de90760ff1899b6734b311d SHA-1: 0bae8f1c64fc63206df91ecb29056e3a0250f979 SHA-256: b31bc592d3df6b31361db32a87fac32cdd082394f2aa2fbc62d6bb507a51ba4e
196 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains a 'Clipboard command execution lure' heuristic, indicating it instructs the user to copy and paste content into a shell, likely to download and execute a secondary payload. Numerous URLs pointing to potentially compromised WordPress sites were extracted, suggesting a distribution mechanism for further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096395f4e779---valanex.pdf
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/4s8dtpjlsocbk8qref4lp2gno0/zafoxotokul.pdf
    • http://mu-rrrc.com/userfiles/file/zosigamotok.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/91b3e676dd8a2d2a04da38a24f4ed241/14311615794.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/8787a0c18dbb7b381afe574735b9241c/romobafewetetafuzutim.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d0cc627293c---kugimanene.pdf
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160acf1c4089e5---denijinupurozov.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a61c75b1ee---bonalenofemasotuzuxara.pdf
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607efbe587bb6---tirixolo.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16089adc0e10cc---rulira.pdf
    • http://botosani.ro/img/uploads/file/93815127137.pdf
    • https://amatnieks.lv/pictures/image/sonodawokudasikaf.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760385765d4---xefagufikufarisew.pdf
    • http://imi.vc/upload/files/59195791995.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/df9a854d87bb189ca9dadddc409fe4a2/40446521380.pdf
    • https://bkht.vn/userfiles/file/8817754463.pdf
    • http://homeopathyhongkong.cn/files/31918932336.pdf
    • https://bfull.ru/uploads/files/55898601096.pdf
    • http://namadagaskare.ru/ckfinder/userfiles/files/zekexawusixajep.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf7d48ea85f---tasumeridazasukubofavamug.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef46a27ed9---33196272731.pdf
    • https://cafesca.mx/ckfinder/userfiles/files/40952765575.pdf
    • https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e4f11782c---fofofetital.pdf
    • http://usaoxin.com/userfiles/2021-6/file/sawawe.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=what+is+ft+stand+for
    • 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_off0000e013.bin
0247ef027d4cb3da4e592821c1947c834a0269cca86d957c3585768c13cb817d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE013 17864 bytes
font_01_sfnt_off00010eb1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EB1 16792 bytes
font_02_sfnt_off000126c8.bin
1a54ef97cd5e61ea2a717284db11fc2f4acf7e7aaec9132087e0e5c74148a337
pdf-font-stream PDF embedded font (sfnt) at offset 0x126C8 10264 bytes