Malicious PDF — malware analysis report

Static analysis result for SHA-256 4011042957b6b95c…

MALICIOUS

PDF

71.4 KB Created: 2021-09-06 10:23:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 113f58e33cb503ca88cbafdb6bbe15ff SHA-1: ce85c200b3212d478befe22f97c40788ffbb3bd9 SHA-256: 4011042957b6b95c64117a6da7ab6b042558412516895763ba57a95e69a54773
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as a link farm, with many distinct hosts and URLs pointing to potentially compromised CMS upload storage. The ML classifier and ClamAV also strongly indicated maliciousness, specifically classifying it as a phishing trojan. The document body was unreadable, but the presence of numerous external links suggests an attempt to redirect users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://jyjwqj.com/uploadfile/file///2021060612074546.pdf
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b954d7f523---bokazimivugaworenejeri.pdf
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/b53b5a96997176e22b847a0cd344cc5e/zusotarerodirij.pdf
    • http://zge-led.com/luodan/images/userfiles/file/tawukabilexulo.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/du0ec1avps92fe9dcdkffr50om/12239177131.pdf
    • http://tranhdaquydep.vn/upload/files/83718081458.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/m8gqm4l24mrtiak81je95il93n/virajojupebuxotilipelak.pdf
    • http://csc0535.com/userfiles/file/20210708002627_l6x26m.pdf
    • http://botosani.ro/img/uploads/file/zopamawu.pdf
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160befe3f370af---13923479161.pdf
    • http://americanpetrochemicals.com/customers/CMS-IMAGES/file/tukugesojesaburat.pdf
    • http://kolbiko.com/images/uploads/file/lugevewanokoravijumazus.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093a13b8a624---xegam.pdf
    • http://dharmapremipariwar.org/userfiles/file/4129347013.pdf
    • https://avgdesign.com/userfiles/file/dedomafuneruxudujal.pdf
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/63666c7e878fb75150120677bc71b3a2/53637218083.pdf
    • https://areicon.com/images/file/27097828442.pdf
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/paos25hrss57aommguivbbis4c/fetade.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a7286e27c5---82727375968.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16098338e82167---73110238921.pdf
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/33bc2b7e659c9d42dcd30c929807be75/jipelekobusirepebula.pdf
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16130eb20c56b8---60013943884.pdf
    • https://partnermind.cz/images/files/puporogavedekavisagilunuj.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/51933174244.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=psychopathology+theory+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_off0000b846.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB846 16792 bytes
font_01_sfnt_off0000d058.bin
141c1413998883b22ab1e9033b883ccaf4938ba57f6c1d96cddea66cea92c82e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD058 15372 bytes
font_02_sfnt_off0000f73e.bin
8be670dfb89c4669e0dca3533ae8f47d6758f08c54fc2c4c9bd904f59daa6928
pdf-font-stream PDF embedded font (sfnt) at offset 0xF73E 10816 bytes