Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd435b508e35538c…

MALICIOUS

PDF

93.0 KB Created: 2021-06-25 22:02:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cf27f89b1ae9b792e2057aae5d958f1f SHA-1: 62a3f2d579dea5676556b4098e1d04fcc1e5d942 SHA-256: cd435b508e35538c42c6f213bd5b93333e531d58149e255c785a0d7d7cea573c
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file flagged by ClamAV as a phishing trojan. Heuristics indicate it contains a link farm pointing to compromised WordPress upload storage and a fake download button lure. The presence of a callback lure suggests a phishing or tech-support scam attempt to trick the user into further interaction. No scripts were extracted, limiting the analysis of the payload delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9243a29be---nixugaj.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609839aed8b41---74276699688.pdf
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/59b591e6fe7fb225cb7c7348428e57bb/79463918790.pdf
    • https://autoteam.in/ckfinder/userfiles/files/bijiwemepovatusika.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/bd1b651c2b326a2af9f0124edd9d28a2/45685099579.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160948fcb9d817---muvitesovabu.pdf
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/e88973cad814b358524d5687c506ed1d/tutanazamoxofenonalubovu.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b4a5a2c98f5---43512394251.pdf
    • https://bahispesinde.com/gnc/veri/_files/nisozuxowufuganu.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a67f1c38318---93081553022.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609552a8e4e9d---17175823592.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160ab672643a61---25039570806.pdf
    • http://mp-hd.de/data/aktualnosci_imgs/file/10247176962.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a795e7d4157---vegedironegafelep.pdf
    • https://geneticapanama.com/userfiles/file/sovibowarigirimufeferasix.pdf
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bc2cae9521---pevatezitotenupurowisor.pdf
    • http://abogarestudio.com/userfiles/file/wujiwuwumebamikododozapop.pdf
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c96e95e1db7---pederofelifil.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/2l1erhb8adt44m3m53sb762kc3/89736351755.pdf
    • http://renovator.cz/files/file/sulutibedat.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=certificate+of+fitness+s95
    • 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_off000103bf.bin
5036a8243a25212af85dc27fefa070f870b33d6e4f6c9453c327cdd54963619f
pdf-font-stream PDF embedded font (sfnt) at offset 0x103BF 18676 bytes
font_01_sfnt_off00013520.bin
c575dc4c1326a6749d40634cd2b4d87ad86996a1c7470600ca33e7dade7a8ad4
pdf-font-stream PDF embedded font (sfnt) at offset 0x13520 10616 bytes
font_02_sfnt_off00014da2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14DA2 16792 bytes