Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b44aa5b42dd2172…

MALICIOUS

PDF

88.8 KB Created: 2021-08-12 15:42:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 85be97732e8349ff24e836769d827533 SHA-1: fe9f73030e16a947710f4010c36b29a2d89b5098 SHA-256: 6b44aa5b42dd21720fba3310b05994ee7c7426a4f186d5da312ce4f0ad488761
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other domains, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farms indicates an attempt to exploit users through deceptive links, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9600

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://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160e8bccd59fd9---9231797101.pdf In PDF document text
    • http://castudio.eu/userfiles/files/nazatavixi.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/550ddd65e81691b5d87d730b1ada90db/zukanimovaluvob.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/b6b55b51c25a3da0ecaf1a3b5bc15d87/lijowisuxonototifimigi.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/2t96qjcm3f7l2vv6djr17f5up8/dadililuvomunuwaxulumej.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/be1mjvpcrjcs7vdi999p0fit3c/60804827643.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/misobobugarezawe.pdfIn PDF document text
    • http://vogiantinhmach.com/media/ftp/file/sijagetibesizukem.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/nuxadipitujibataji.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/63232206145.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/nolifavag.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160da875a46064---maraxegazojujupojodi.pdfIn PDF document text
    • http://beergolfers.com./blog/images/file/41611941298.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/badiwabezedemafupavosenun.pdfIn PDF document text
    • http://barrospizzadb.com/uploads/files/mujufepibe.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/fitopojufexe.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/fupupigo.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087fb372bd76---12302318171.pdfIn PDF document text
    • http://ipllaser.in/uploads/sovinabosat.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c0332239de---xipifejofepowifijereg.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1611340096fe8c---kojanok.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/cg5mub8maagi33qfc6o17mge44/molubegofadidibusuj.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/7tq4afm7d8qs18paajdpj0rhth/37279613146.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=problemas+de+valor+inicial+ecuaciones+diferenciales+resueltosPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8A9 19540 bytes
SHA-256: 42908790751bf7853685bec0c7683a6685193e50a60188bbc5a3fb5e0b51a521
font_01_sfnt_off00012bc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC3 10944 bytes
SHA-256: ca39069fa6c51d0c4d485911c3aa036635d028c8d1a0147a86b31cf00855fb08
font_02_sfnt_off00014524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14524 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1