Malicious PDF — malware analysis report

Static analysis result for SHA-256 5cddb5aae6e2522a…

MALICIOUS

PDF

88.7 KB Created: 2021-06-26 14:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b1f18c8f8847a510abd24e375515d13b SHA-1: b813e4ec2e477909a17f4e4781d51fbcab2ea211 SHA-256: 5cddb5aae6e2522a744c13d4f42a23c9e65d412e7efee62cbe77c6ca73a9f343
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous external URIs were found, many pointing to compromised WordPress upload storage, suggesting a phishing or malware distribution scheme. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, which is often used to create malicious PDFs that redirect users to external sites.

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://crysiq.ru/uplcv?utm_term=the+cast+of+law+%26+order+organized+crime
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16071419e1581a---80883739766.pdf
    • https://activepymes.com/pub/file/kibimorovololurukagavi.pdf
    • https://balaji-technology.com/userfiles/file/82320519994.pdf
    • http://blevy.com/ckfinder/userfiles/files/72732480901.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/r8k5nc6s3buip7v4r68npp72rf/jugiruxegewad.pdf
    • https://parklanehotel.asia/userfiles/file/43220923651.pdf
    • http://longhornrings.com/clients/0/08/08da48574b41509ac7bedcf2500dc652/File/fajakoruvepezinuwebe.pdf
    • http://upbfassadenbau.com/upload/file/gubulesemalomewususa.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c852588e188---fixujegawoxate.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607005d7d498d---dodagofavimokitipabomuwi.pdf
    • http://banhangcongnghe.com/upload/FCK/file/22802800137.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae0ecb11d62---xizumixigas.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b554abd334a---vofan.pdf
    • http://acpiindia.com/userfiles/file/74321438182.pdf
    • http://travelshops.pl/userfiles/file/bevisirulum.pdf
    • http://clasesholandes.com/userfiles/file/47088438787.pdf
    • http://asokmontridental.com/userfiles/file/41098960499.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c576c8ef686---45345888561.pdf
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/798a0d4e71f833e6b73d6ab2fcef221e/veladosawenerimadi.pdf
    • https://retake.dk/ckfinder/userfiles/files/81402205478.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080a4e6ecea5---niresuzu.pdf
    • http://urbanconstructions.org/images/uploadedimages/file/81920189486.pdf
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/651218d0ce806ca37f52e5fa792ff449/98296781540.pdf
    • http://alphasigmaoverseas.com/userfiles/file/kaxom.pdf
    • 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_off0000f916.bin
e795b06527e881a045ce6949137f9f0e00a99a42a14c08c8558960909febf993
pdf-font-stream PDF embedded font (sfnt) at offset 0xF916 10184 bytes
font_01_sfnt_off0001102c.bin
e01384088367d9708650b9b8c1d05f6b37d6d627bcda7065c59755b33dd51018
pdf-font-stream PDF embedded font (sfnt) at offset 0x1102C 17596 bytes
font_02_sfnt_off00013dc1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DC1 16792 bytes