Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a75c81e7fd4f15f…

MALICIOUS

PDF

70.0 KB Created: 2021-09-27 18:15:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8f05e53b3e7878a89dc8bbc3b45a3557 SHA-1: ac4d8458bab60963436e6285979ac0fe13323db4 SHA-256: 8a75c81e7fd4f15fa077e979ad9a8566ae27aab13bd8a1f9b1cb4050cd0cd1e2
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting an attempt to lure users to malicious sites. The presence of a link farm on compromised CMS upload storage further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://lafiestadelmoto.cz/files/file/borewefolenujumamexo.pdf
    • http://galeriejacqueselbaz.com/userfiles/file/xibolamuvoxiwazutogobu.pdf
    • https://innovaciones-plasticas.com/imagenes_cont/sitio/documentos/87466713691.pdf
    • https://srmhomes.com/images/bulk_images/files/vagemuvapeker.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16135540fc2b97---21290792685.pdf
    • https://playindiano1.in/ckfinder/userfiles/files/jujite.pdf
    • http://www.malagatour.es/ckfinder/userfiles/files/53233616712.pdf
    • http://asbu.net/uploads/FCK_files/file/kaworesebimefizotu.pdf
    • http://dinobajka.pl/Upload/file/3141751478.pdf
    • https://latarnik-kopice.pl/galeria/file/givebalanoxenal.pdf
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/tugur.pdf
    • http://evo-models.com/uploads/userfiles/files/solibikavokaw.pdf
    • http://clinicaveterinariacene.com/userfiles/files/dutaloziledaxago.pdf
    • https://kohphanganhotelandtour.com/userfiles/file/74100575785.pdf
    • http://e2ingenieros.com/ckfinder/userfiles/files/97175623645.pdf
    • http://myrbacken.se/login/ckfinder/userfiles/files/69251860903.pdf
    • https://tbsva.org/Upload/files/20210901072016.pdf
    • https://managedentalclinic.com/ckfinder/userfiles/files/18059825004.pdf
    • http://nhakhoauytinhaiphong.com/upload/files/jusanapopupuvuvakixaza.pdf
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/19692367981.pdf
    • http://keralastatetailorsassociation.com/userfiles/file/ninuvonimalusob.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161396ab481e17---winujososebexivuzupatoko.pdf
    • http://ckudzcssffhhj.handysociality.com/upload/files/jixavaxulixaxobu.pdf
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5dc35aef4---gaxibimasixoduvosep.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=cheat+billiard+8+ball+pool+android
    • 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_off0000b06f.bin
1ddf069d9d5edd5fd5845d930c022331470ed09fed0b07732d9d447d1e9fc668
pdf-font-stream PDF embedded font (sfnt) at offset 0xB06F 10700 bytes
font_01_sfnt_off0000c8a8.bin
68eb480b992abe3d48f5522b07b9e9a8b9e476017bd2919ba8cbd616ade3334b
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A8 15928 bytes
font_02_sfnt_off0000f0d4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D4 16792 bytes