Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a72572982dc6dc…

MALICIOUS

PDF

84.6 KB Created: 2021-07-01 21:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 61ff2cc1645b4341da59bafa2b35d42b SHA-1: 1438acf618dfab34be082482949f6cbbb09c926f SHA-256: 91a72572982dc6dc12694d2add826d690499cde3250d53abf9345114fa59357d
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating the file's primary purpose is to redirect users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://inwebjor.ru/uplcv?utm_term=valency+of+magnesium+in+magnesium+oxide
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/g5cokks61g2he43qu9qa6rdgi4/47565847862.pdf
    • https://wegofa.com/userfiles/file/midowajapaxigiwiwojosowam.pdf
    • http://caycanhtuyhien.com/uploads/image/files/10858074816.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca146434f0---minefevigedatojupagabewi.pdf
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/67855865814.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160c2acd72fb75---dudujinufubomubunate.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b050a3456a1---mepokunomebosubevilapi.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e832e2a04---2725380830.pdf
    • http://greenld.com/userfiles/bazidosidizofebotikifis.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/8518rujq5mfsmhf3455b66lt21/50468702518.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/mh5p7id742eakgtdhne9oe9257/60213914417.pdf
    • http://casaatlantida.com/userfiles/file///bavimowuzawuxeraxofinez.pdf
    • http://atenngo.com/admin/sites/site/documents/45725412939.pdf
    • http://roland-toys.eu/userfiles/file/99899168962.pdf
    • http://suacona.com/clients/16856/File/89709058913.pdf
    • https://bloomeng.com/uploads/50814045137.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/160c851909f373---nanimun.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff1ce55891---49865208124.pdf
    • https://holocaustresearch.pl/nowy/photo/file/79028207910.pdf
    • http://grandp.ru/userfiles/file/fojowaxojijiku.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0cf52d8344---nixagikafotesowodulegib.pdf
    • https://mednet.mk/public_html/upload/userfiles/file/18480972256.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/68b092597309591bbc569938eed9b490/dukixuxagige.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_off0000e88f.bin
be39b84d37d389a06068abc535d27394a805914484b722e8e0b417f6cc48c14f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE88F 16796 bytes
font_01_sfnt_off00011425.bin
63e2160d316a101d1389b4d3b96ba6ead21ae02649435c0a000f5f72e9d985eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11425 10908 bytes
font_02_sfnt_off00012d36.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D36 16792 bytes