Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac639a1cf15c8bdc…

MALICIOUS

PDF

86.5 KB Created: 2021-08-20 00:57:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 954d9b00ad8f38b546f254d19d828df8 SHA-1: 97d8a337f0f37d447f7b2a27ae189ae43a7ebbd5 SHA-256: ac639a1cf15c8bdcc7810b6c5abd42d1e37083c5988b7b4ad8afa357a59b8a0e
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically points to this behavior, suggesting the document's primary purpose is to drive traffic to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://drsaman.com/files/kidenizotogipitif.pdf
    • http://stphilomenaonline.org/userfiles/file/14921889340.pdf
    • http://receptlap.hu/files/gomodijerowivo.pdf
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a6fc8dd48ba---kivawuzomudexabavetepemug.pdf
    • https://dnmpaint.com/sdcc/images/file/58627135476.pdf
    • http://www.yoko-ono.be/images/userfiles/file/sofidomuzefumixel.pdf
    • http://kientrucsangtrong.com/plus/files/83170156965.pdf
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/78cd648bfc27f3aeb2569efcb6eeaa38/pibipaluwinufizokevixo.pdf
    • http://pierrevillers.fr/mairie_files/file/raruzokakenesufepefib.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a838950be50---82321219575.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609bf9460f344---xefilijuwurowo.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608827ec022e8---pizivudexaririgasefe.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/321067e6265c8609a593263ae022ab63/94038922898.pdf
    • http://sushi-belovo.ru/files/43872691013.pdf
    • http://fotossc.pl/_files/file/zazijaval.pdf
    • https://cordovajewelry.com/images/file/talunerima.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/4bd861ce9480e9c8f1c9ed8c9aa370b6/xanixineditawu.pdf
    • http://polaryachts.com/res/wysiwyg/file/zabefaporenifetosoxalolew.pdf
    • http://animationcoach.com/userfiles/file/29525144077.pdf
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/028028482ae4197cadbbb7417a6f1eba/turiwakozazojonixa.pdf
    • http://1970lions.com/clients/5/57/57eb30a5877ba0c7834658d164206012/File/virarelubujifezegawapad.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/25cb2bbe9a81c3b71edb32f2edce1eaf/magodolufaziginomofel.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b84e7863f---53008287821.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/c046120ac28f315bdece9eec99f34cf6/joredegupimevi.pdf
    • http://tai-yang.tw/taiyang/upload/file/riniwazugavevomululozifow.pdf
    • https://recrut.com/files/files/11410849134.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+clear+cognizant+written+test
    • 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_off0000e7c6.bin
33353d9153e83abfc48b20c6b03bb9e6bd893dfa2d01a66c7e2362f79296c0d8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7C6 10544 bytes
font_01_sfnt_off0000fffb.bin
aaa1db6624d651949837ec1c7e844e93e4c908ae2e525b6a4bd1cd20b8ee298f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFB 18928 bytes
font_02_sfnt_off0001323e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1323E 16792 bytes