Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b704bc6e7608b3c…

MALICIOUS

PDF

84.0 KB Created: 2021-06-26 21:04:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7bb8fcfd2f416d3d521b05ff64062477 SHA-1: 05f6bd9d1b868a0e1b7807aeb2e74e2b136885a9 SHA-256: 4b704bc6e7608b3c17d82fd94809453403e9595316d91162e3ff794778ed61aa
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. The document body is heavily obfuscated and appears to be generated content rather than user-readable text, further supporting a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608184951eef5---5648927485.pdf In PDF document text
    • https://beyondpins.com/calisma2/files/uploads/98660391513.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/cc5a97a9f021d513f23f14f543785e63/bamurifuredefazokap.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/74298795921.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca643b71b6---99520620928.pdfIn PDF document text
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/pijaxawiluxaxoso.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/euf1ags6u8c1tpsrp9gp19qb3i/rodulasujukukupufuxovusim.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/0d963918be5998030209f4282fadadf1/xivozotuwiko.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a637a7088---56013412928.pdfIn PDF document text
    • https://tenfci.org/userfiles/file/kizidewapeba.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/50343930327.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b14bc7ee728---mowuzikita.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/547b9c0939f84f0f3de99968225fe98b/17523159076.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf63d59eb9---36847327599.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/gadumetepavirobu.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/3a98ca1c2815843c186ec5c5523ace2c/90819676684.pdfIn PDF document text
    • http://evansmedia.ca/userfiles/file/sixugaradidavaz.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160adc3fe7216c---ragutunadiviwizawofise.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/gufepipebi.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/4a21e7c9e54316fe10d3c705e658be7b/54533583748.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/disigukimupal.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/82r63k423tlv6s5vnvlhnaig0c/jemagofad.pdfIn PDF document text
    • https://girilawfirm.com/content_files/files/60617472774.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/c195e99613d407d16a8ed88f3c3476fc/famonivurigizawi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=going+color+blindPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/98499090066.pdfIn PDF document text
    • 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_off0000e879.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE879 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001008b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008B 16908 bytes
SHA-256: 6b40edaf45a5f2e395bca926d468d997a6558c84ad7794679505d731bf9ab864
font_02_sfnt_off00012c9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C9E 10164 bytes
SHA-256: c173398e7c6599c2310f141c5646ccbe55c9669978cdacb7e829a642f8078036