Malicious PDF — malware analysis report

Static analysis result for SHA-256 83083ddf7a90bb25…

MALICIOUS

PDF

83.1 KB Created: 2021-09-05 03:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 563d95602476dc9d1f726c1f65a0ada7 SHA-1: 39175351a7064dd93aee2585bd126c19cbc2f00d SHA-256: 83083ddf7a90bb254e1716b0e3ea526a884fb1529bbaca24c229d149981dca1a
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating it likely exploits a vulnerability or contains malicious content. Heuristics identify it as a link farm pointing to compromised CMS upload storage, suggesting it's used to distribute further malware or phishing content. The presence of numerous unknown URLs reinforces its role as a distribution point.

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
  • 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 http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/wugizivosobadon.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1f2fc8a48---91524766398.pdf
    • http://backupcenters.com/userfiles/file/zemuv.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/vt30qgjiblfltua3f9ent7caft/zelupotelibej.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d052ba5a5a0---86268098837.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/06276408bf9384695ebc4974f6e3823e/tamegaxa.pdf
    • https://wineart.online/userfiles/file/kesupuzugiko.pdf
    • http://nwatchonline.org/userfiles/file/kukezovoxapiw.pdf
    • http://lamgi.pl/ckfinder/userfiles/files/gonajetisijufes.pdf
    • http://ttmplus.com/userfiles/files/73911467762.pdf
    • https://kund-in.com/userfiles/file/wawobokuzotod.pdf
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/dbf1654473e4d87397ff568c58abc8ff/19553819201.pdf
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c675cc81ae0---89025301031.pdf
    • http://greenmodels.ru/uploads/files/kabodu.pdf
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d74b77418e7---xijoko.pdf
    • http://ediljolli.com/userfiles/files/84855777959.pdf
    • http://karmand24.ir/basefile/ehotel724ir/files/lajixibofaraja.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099d8eddb166---pawefugugulidi.pdf
    • http://senseoftourism.dk/userfiles/file/wexupefepajegosipatonenom.pdf
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/4128658334.pdf
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16072e55a1f108---bukarokavakobifojotug.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ad473e090d---84628900913.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=como+hacer+manualidades+con+carton+corrugado
    • 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_off0000dbf7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF7 16792 bytes
font_01_sfnt_off0000f40e.bin
1ac8378c9ebd24f5650c0488a0600137f5e1299a5273389c95cb033070fa19f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF40E 10948 bytes
font_02_sfnt_off00010d03.bin
57f09d21c830105be7e1e3a0f31ed9a38e0c47a3584486fd005c6ce3204d3622
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D03 18724 bytes