Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef00dd9aefc9690e…

MALICIOUS

PDF

84.9 KB Created: 2021-09-01 23:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9af2a4840fd7224a3f7d0884f79942ad SHA-1: 3dfcde794f7fa3f61a928505c55acae828fd83c9 SHA-256: ef00dd9aefc9690ef05c12d5398ad814fa02c19abe7e85655274a2d51bec43ab
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to various domains, some of which appear to be compromised. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://big-blue-bus.com/pics/fotos/1/file/79736435543.pdf
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/lubijire.pdf
    • http://firewheels.pe/userfiles/file/winuwafozulufiveragokedew.pdf
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1608e05b3b860f---kosasisi.pdf
    • http://baugeraeteverleih.de/benutzerdateien/belabu.pdf
    • http://ilksolar.com/Images/Media/files/duwig.pdf
    • http://career-id.org/ckfinder/userfiles/files/1631416495.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d90264c369---jedupamu.pdf
    • http://cn-daomeng.com/upload/userfiles/files/13fe5d63e0fbaf19c56080c6cda6b1ef.pdf
    • https://niboparis.com/upload/fckeditor/files/5114187243.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608628bbc87a6---83566513051.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f077f10fe90---jonimebos.pdf
    • https://gencshow.com/upload/ckfinder/files/palamutuxawiwomewipe.pdf
    • https://harkakotony.hu/UserFiles/file/58579985020.pdf
    • http://guides2alpes.fr/uploads/file/17475212973.pdf
    • http://dunajecbiala.pl/upload/File/domizopufusagubaleri.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/161031460d44d6---6444048755.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607596ff1eb53---latuduvexufip.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1607b04f4249ce---denobakobuzarozedo.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d0abbbc3238---86646477609.pdf
    • http://ash-graphy.com/userfiles/file/79202055575.pdf
    • http://orgue-chantepie.info/FCKeditor/upload/file/pasaxunaduruloxo.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/t5bf48e7i5npc8gpdh5a7ok9b3/gidog.pdf
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/n79qrinplprvb3ucimqn8f137i/56568079713.pdf
    • http://helder-effect.nl/userfiles/file/xowekexodiku.pdf
    • http://romanakladatelstvi.cz/userfiles/file/devojejupilufigavuzadesuf.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=find+linear+equation+from+table
    • 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_off0000e465.bin
7b70384933124a3cedfb06ac0bc712e218c856ba2294ee32dddbfe53ed7e99c3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE465 18660 bytes
font_01_sfnt_off00011499.bin
5d0dcb01bdc722919e65a9efc6162a1437e33dd8cef4335dbf074fa89bd9a650
pdf-font-stream PDF embedded font (sfnt) at offset 0x11499 10708 bytes
font_02_sfnt_off00012cdd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12CDD 16792 bytes