Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a76b60738568ed7…

MALICIOUS

PDF

84.3 KB Created: 2021-07-08 07:54:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 77392c2b4460dc2a5b37306d65b3d4d3 SHA-1: 23d8e5ae9d239e14724e778464b0d893c9295a3b SHA-256: 5a76b60738568ed708739c8e4fd7bccd21f3237017c5dd3947220dffc95c472a
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URIs, many pointing to potentially compromised CMS upload storage or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL structure are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://bouwservicewinthagen.nl/userfiles/image/file/55550016686.pdf
    • http://romanakladatelstvi.cz/userfiles/file/pugiforarakenobife.pdf
    • http://www.aqsclimited.com/EditorImages/file/sewuxadopofu.pdf
    • https://atcotourismtravel.com/userfiles/file/78299690025.pdf
    • http://savalis.ru/userfiles/file/41823333108.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160dae38aac173---xizikimakufeja.pdf
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/beninubagavolofifapame.pdf
    • http://theettiaresottawa.org/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/47543263972.pdf
    • http://grapevinewinerytrail.com/clients/876125/File/52833496253.pdf
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/e5e97c975746703c88c4e2a7a3656d3c/zopiripijosunoxij.pdf
    • https://sieuviet.net/webroot/img/files/gotep.pdf
    • http://thecreditcrisis.net/clients/73966/File/wenizagurasul.pdf
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/sls8g79ilj51m8so7br6i8f0h5/29581871021.pdf
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/5dd096429eb576267d8ad103e6463bb6/25506561421.pdf
    • https://rainbowfurnitures.com/files/files/64318769771.pdf
    • http://slp61.com/clients/e/e2/e296dcecfd7d10ffef0cc83fef253c72/File/ribokovizigukupiwob.pdf
    • http://seamcc.com/UserFiles/files/40746421172.pdf
    • http://sbox-technology.com/upload/datoteke/fejazabogizuvivudonomete.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/16073c8ae5be79---11465663539.pdf
    • http://extracam.es/app/webroot/arxius/file/lefofejog.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/r7nje2nbslspug3p275hsgjjt7/pogevupapekuwejotigomi.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a34eac6de05---33101716106.pdf
    • http://uniroll.pl/user_images/file/bedipunivaxemasedoseguvi.pdf
    • http://thetownsendfamily.net/clients/a/ab/ab79602242cca8f930cd52af13df1d51/File/novuz.pdf
    • http://buergerforum-tirol.at/file/61743537062.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=menopause+after+55
    • 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_off0000e96a.bin
bb6514b5755bd2cee4c1bef19b4028f567423368002881da682d4b544d104b90
pdf-font-stream PDF embedded font (sfnt) at offset 0xE96A 16532 bytes
font_01_sfnt_off0001142a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1142A 16792 bytes
font_02_sfnt_off00012c41.bin
9adc47a9316ce4f5bc692a584ed1b16bbb9c2e2b4fd01a206f982142e3bc8f4d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C41 10440 bytes