Malicious PDF — malware analysis report

Static analysis result for SHA-256 88f853e39ff3c7e5…

MALICIOUS

PDF

87.7 KB Created: 2021-09-09 13:33:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: dfbf5df32d38cf381b09f74bc5338090 SHA-1: fa448749ee5ba61d5198e92f450d21263bfb6ca4 SHA-256: 88f853e39ff3c7e580dbf305dbe60e429254c1609d13dd7a4d67e26a5211bc18
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to potentially compromised or disposable hosting, a common tactic for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as Pdf.Phishing.Trojan. No scripts were extracted, but the structure suggests a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://th-hl.com///upload/files/lukuwatapugobil.pdf In PDF document text
    • http://chokmanee.com/userfiles/file/86843410406.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/a4f7b1f2e142fa632f0b62a954e490f6/nonaw.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/81026964381.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/jojeze.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/susuwinisosoboxedevaw.pdfIn PDF document text
    • https://dobre-akce.cz/media/files/file/26322247186.pdfIn PDF document text
    • http://unicorn-furnitures.com/d/files/morikenomifemufije.pdfIn PDF document text
    • http://nmways.com/uploads/fckupload/file/61191526488.pdfIn PDF document text
    • http://adidravidar.com/ckfinder/userfiles/files/45295855281.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161385e7e3a324---79442881151.pdfIn PDF document text
    • http://darec.sk/files/files/fukugowelusuxamuzuxa.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/sijuluxusa.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/lipedateparo.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/14q6k9o9s956r7g017btgmtd57/45658186871.pdfIn PDF document text
    • https://patc.fr/imagesfile/38488964199.pdfIn PDF document text
    • https://fertilizerproductionprocess.com/d/files/97630335724.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161397e968b91e---wekebutememo.pdfIn PDF document text
    • https://campermagazine.tv/public/file/61005008901.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/zofikevedemigukutepi.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/jibujakenamutilagetumoron.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/42360259832.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/rivokinokexixafulob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=the+intelligent+investor+book+free+downloadPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • 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_off0000ef4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001075e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075E 18456 bytes
SHA-256: fdad18b5b10f24507c6045523c447a434417a48d97ad53326639542f3799e2a4
font_02_sfnt_off000137f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137F1 10980 bytes
SHA-256: e4795695ddf75e73b5fd8166eb022f06e9f30dc13ef0a1daccba6f83d7e2f2ca